SammyQ
Established Member
Corrr!! That's heavy duty gear Daniel! Never used it, but I concur, that would stop damp for sure! Sam
Damp in garage wall
- Thread starter Marineboy
- Start date
Help Support UKworkshop.co.uk:
Corrr!! That's heavy duty gear Daniel! Never used it, but I concur, that would stop damp for sure! Sam
Sam
We ended up going along the whole 2 sides of the house.
But, their damp problem was solved.
I'll see if I can't find some more pics. It was a delicate operation.
SammyQ
Established Member
"It was a delicate operation."
Brohahahahaha!!!
Brohahahahaha!!!
Sorry only just seen this thread, the first thing to check is where do the garage gutters discharge, or any other adjacent buildings, most damp problems are caused by rainwater or splash back, rarely is the problem so called rising damp, which is a fallacy perpetuated by the injection DPC industry.
Marineboy, I have not read all the posts but another avenue you can pursue is chemical injection damp proofing, this is very effective done properly and cost effective compared to other methods.
Have a look at Sovereign Chemicals https://www.sovchem.co.uk I know personally of several jobs where this was used all were successful. If you contact them they will have a local installer.
John
Just seen MikeJhn post above --he's entitled to his opinion of course but mine differs 100% !
Have a look at Sovereign Chemicals https://www.sovchem.co.uk I know personally of several jobs where this was used all were successful. If you contact them they will have a local installer.
John
Just seen MikeJhn post above --he's entitled to his opinion of course but mine differs 100% !
Last edited:
SammyQ
Established Member
MikeG? Calling Mr. Garnham!! I know EXACTLY what his response to this would be!!
Lons
Established Member
There is no point whatsoever in a chemical DPC as it won't work in this case where the external concrete slab is far too high and will definitely be higher than the internal floor and and dpc if there is one installed, the only effective solution is to cut back the external concrete and reduce ground level. I've encountered this many times and had to correct the issue or advise the removal of soil where that was the problem. Hard surface is often much worse as water pools and splashes resulting in inevitable water penetration through the brick and mortar.
The subject of rising damp is a very different matter.
Marineboy
Established Member
I'm no builder but I've read enough to form the opinion that rising damp is a myth and that chemicals are a con. Reducing the ground level seems to be key.
Jonm
Established Member
Marineboy, I think you are on the correct track. Firstly I would check the gutters are all working or fit some if none are present, someone else has mentioned this.
The ground outside of your garage should be 150mm below the inside floor level. If you decide to lower the concrete then a disc cutter and breaker is a good idea as already mentioned by others. Remember that a large 300mm disc cutter (petrol or electric) is a bulky machine and will cut to a depth of say 120mm, ppossibly not enough to cut completely through the slab so you may need a second cut so the machine is inside the trench, so the wider the machine the wider the trench, you could be talking about a 450mm wide trench, it all depends on the depth and strength of the concrete. There will be a lot of debris to be removed and reinstatement.
You may be better employing a builder who already has the tools. Alternatively you could try a 230mm electric cutter which is smaller and an ordinary sds drill with hammer action, may work if the concrete is not too strong.
The ground outside of your garage should be 150mm below the inside floor level. If you decide to lower the concrete then a disc cutter and breaker is a good idea as already mentioned by others. Remember that a large 300mm disc cutter (petrol or electric) is a bulky machine and will cut to a depth of say 120mm, ppossibly not enough to cut completely through the slab so you may need a second cut so the machine is inside the trench, so the wider the machine the wider the trench, you could be talking about a 450mm wide trench, it all depends on the depth and strength of the concrete. There will be a lot of debris to be removed and reinstatement.
You may be better employing a builder who already has the tools. Alternatively you could try a 230mm electric cutter which is smaller and an ordinary sds drill with hammer action, may work if the concrete is not too strong.
Marineboy
Established Member
Thanks Jonm. My SDS breaker did the bit you can see in the photo but it took some time and effort. Just a question of patience unless I pay to get a pro in.
toolsntat
Yep, I collect tools and tat
In the time it takes to organise any other options you could have run a line of (10mm?) holes along the slab with your SDS drill. Do a line or two the short way to section the break up and it should break out with moderate effort.
Of course, if you want a neat, cut edge, ignore the above
They look like smooth hard bricks, engineering?
Dare say that paint won't be letting the mortar dry out much either.
Cheers Andy
Of course, if you want a neat, cut edge, ignore the above
They look like smooth hard bricks, engineering?
Dare say that paint won't be letting the mortar dry out much either.
Cheers Andy
Marineboy
Established Member
Good idea, I will try that. Yes, the bricks are quite hard, not sure if they are actually engineering. I don’t think the paint has much influence as the damp is on the two courses below the painted one.
Noob here but an experienced builder.
You can see the damp on the first couple of revealed brick courses but you're going the right way however I can also see from the size of chippings that your breaker isn't really man enough which is why you're a little frustrated by your lack of progress. Go hire one that's a lot larger to do the job efficiently.
By opening up a good channel between the wall and the slab and you should see an improvement fairly quickly. Using a concrete cutter is a bit overkill for what looks to be a patio so you can lift the slabs and make good the concrete edge if it really needs it when you're re-laying them. If you're really bothered about that base edge before using a breaker stitch drill it with your SDS so it breaks away relatively straight and by careful use of your breaker's spade chisel you can tidy it up further. That should really be adequate and besides large concrete disk cutters are noisy, messy and potentially quite dangerous if you're inexperienced.
Once you've damp proofed the wall however you choose to do that I'd probably just back fill it with gravel/shingle possibly over a field drain, even a field drain is a bit OTT tbh. Tanking the outside wall and back filling with shingle should do it.
Edit: The other thing to note is the gravel infill used against the garage wall also has quite alot of soil trapped beneath it which also acts as a water/moisture trap. Before you proceed any further, clean that channel out completely. If what remains is a solidily cemented unbroken channel with a decent incline and run off it maybe all you need to do.
You can see the damp on the first couple of revealed brick courses but you're going the right way however I can also see from the size of chippings that your breaker isn't really man enough which is why you're a little frustrated by your lack of progress. Go hire one that's a lot larger to do the job efficiently.
By opening up a good channel between the wall and the slab and you should see an improvement fairly quickly. Using a concrete cutter is a bit overkill for what looks to be a patio so you can lift the slabs and make good the concrete edge if it really needs it when you're re-laying them. If you're really bothered about that base edge before using a breaker stitch drill it with your SDS so it breaks away relatively straight and by careful use of your breaker's spade chisel you can tidy it up further. That should really be adequate and besides large concrete disk cutters are noisy, messy and potentially quite dangerous if you're inexperienced.
Once you've damp proofed the wall however you choose to do that I'd probably just back fill it with gravel/shingle possibly over a field drain, even a field drain is a bit OTT tbh. Tanking the outside wall and back filling with shingle should do it.
Edit: The other thing to note is the gravel infill used against the garage wall also has quite alot of soil trapped beneath it which also acts as a water/moisture trap. Before you proceed any further, clean that channel out completely. If what remains is a solidily cemented unbroken channel with a decent incline and run off it maybe all you need to do.
Last edited:
Marineboy
Established Member
Hi antdad, many thanks for that really detailed post. It certainly gives me hope that the task isn’t perhaps as daunting as I first thought.
You're welcome, as I said (if you got there) clean that gravel channel out next to the wall and inspect it first. IF you go ahead with trying to dig out a channel too you need a much more powerful breaker, that concrete base looks particularly hard but nothing you shouldn't be able to overcome with the right tool. ATB
A.R
Member
You have one heck of a problem. What I would do is build a single width block 4" thick about 2" minimum from the offending wall up to the ceiling. Make sure you use some DPC between the new wall and the damp wall at both ends, to effectively enclose the damp wall. Obviously this will effect your garage door, but it will stop the dampness which will not be doing your tools etc any good. I would also suggest you use Thermalite blocks not concrete as they are much lighter to handle. Ps I built my own bungalow 23 years ago.
SammyQ
Established Member
If Marineboy were to do that, he would effectively 'wall up' increasing damp. Wouldn't like to think what a good, hard, frost would do to the wall then! Also, it's losing space inside - what I suspect - is an already tight enclosure.
Secondly, see Bob's(?) post re brickies not being too tidy and dropping mortar behind the 'new' wall, thus bridging the cavity, allowing damp spread and rendering(sorry!) the exercise ineffectual and a total waste of time, money and effort.
The posts above, re removing the source of damp, are much more effective.
Sam
Lons
Established Member
Why would he want to do that? He need's to tackle the problem at source which is what he's doing not hide it behind another wall. It's pretty clear what the problem is and the solution to sorting it the only question is how to cut the concrete and unless I misread the original post that concrete is 6"thick which will be slow painful work with DIY tools or relatively quick with hired industrial equipment.
It's a common and something I saw multiple times over the 18 years I owned a small building company, usually perpetrated by homeowners or cowboys who didn't know or ignored the fact that ground level needs to be 150mm below DPC or if that wasn't present then at least as decent amount below internal floor level with any water flow directed away from the building.
Jackbequick
Established Member
You still have unknowns. Likely is that the slab itself has not been properly waterproofed. Damp
course isn't always on the slab...it could be a course or two higher...but it should be there nevertheless.
I'm giving a lot of experience in here...and instead of looking at other people's places I am referring
to my own experience. I have been on construction work for over 50 years so have a 'clue'.
Let's step back and get away from rushing at the seemingly obvious...Get away from the slab and
damp course issues for a while. Let's think about construction work.
Your brick looks hard...so damp would be difficult to permeate and difficult to dry out. Using gas
heaters is not a good idea. The surface damp might dry but condensation recurs and the brick is
still damp inside. The worst jobs can be seen in France...painting sandstone with enamels and
concreting walls where there never was any damp protection. The natural drying of the
stone/sandstone is inhibited
Painting brick which gets damp ensures drying-out is harder than if bare.
If there is no damp course you can fit it and it might be the cure...but don't dive into it. ...you
are fortunate in this way...only one layer of mortar has to be cut out for the damp course to
be fitted as you only have a single brick wall. You are not going to immediately find wet in
the house as you 'must' have a stud wall interior. I'll go into that later.
Sometimes a chainsaw with a tungsten blade is uses to progressively cut the mortar and install the
damp course or chemical barrier. It does not need to be right at the slab, one or two courses above is
ok...but let's think more about the situation...We have a slab which should be resting on impervious
black plastic at the time of the pour and reo /reo mesh laid on saddles...protecting the waterproofing
and spacing the reo to the correct position in the slab.
It's not uncommon for clays and rocks and rubbish of all kinds to be used as 'fill' to sit a slab upon..
The rock/glass/metal not uncommonly penetrates the plastic when the concreters are filling and
levelling. so...the waterproofing membrane may have been incompetently or 'carelessly installed
or damaged at the time...or never installed...or later eaten away.
Let's say the concrete is resting in a water course.(natural or man made) through back filling the site
for the slab ..why would the bricks get damp?..Concrete is porous but it should also be waterproofed
in the mix. The water should be running off or evaporating if the slab is surrounded by earth ...
and usually there is only 4-6 inches of concrete past the wall.
"Rising damp" is a reality but why would it be happening...work that out first....and that's the
essence of the solution.
Inside
That thought brings us to the other issue hinted-at by another contributor...Mortar left in the
wall and water coming downwards.. Mortar or cement flicked into the cavity or even dumped
into it.and hanging off the ties is easier than cleaning-up...but water has to get there to create
damp.. The brickies are long gone before you experience the problems and liquidation is a
run of the mill escape these days.
Some brickies are simply slobs...some are hopeless drunks even when on the job. I've seen
them cut bricks and besser, bricks ...with two men working on same wall...to meet a whole course
out..In one site they worked with a bottle of beer in hand and then left for two weeks to do their
marijuana harvest up in Queensland. That the job was across the road from the Harbord Hotel
was a bonus for them! On that job I've seen twists in pillars with 6 inches of cement slapped on
to make them look square... I was flabbergasted and the builder just let it pass. "Competent"?
You said 'single brick' wall.
Hang-on...Is it damp everywhere? or just somewhere?...is your problem condensation on the
plaster board during winter? or do we have a definite water ingress 'from outside or 'through
the slab' issue or are we barking up the wrong tree?
Your stud wall is likely tied to the brick and sitting on a bottom plate and with a top plate
mostly covering the small cavity. It could be good aged hardwood or pacific island rubbish.
The best timbers are smashed by demolishers when in my opinion by law they should be forced
to recover it...they charge a motza and could well and truly cover it in their costs. Tipping
fees are often high...but they double them anyway and they sell-off what they don't smash..
that's 'the cream'.When doing repairs look for sound old timber and treat is when low in the walls.
One possible trouble arising I will include is termites...they love soft timber...mmmm yummy!!.
..easy on the fangs too. They commonly, I was long ago told, eat alternate studs...so the
place doesn't collapse...like CV-19 our ingrained human stupidity...demonstrated effectively
24/7 in USA has us thinking it/they are not intelligent in their own environment. We are of course
'the master race'.
One of the places water enters walls is from leaking water pipe/pipes inside the stud wall...
and/or bathroom leakage...Water always leaches through the tile grout and leaks across the slab
or the membrane to the walls and saturates the bottom plate and then into the bricks.
The shower floor is first suspect for the major leakage problem if all water pipes are intact.
I found mine was just that....so here's the fix..
In my case I stripped-out the plaster in the bedroom adjacent the shower area..
the area was saturated. I stripped the plaster out of the whole wall under the bathroom
window (behind vanity ink and toilet) Bxxxxy termites everywhere!...in both walls but
only up to about two feet why eat leather when you can eat fillet steak) .
On termites....
Termites like dark...light sees them moving away so exposing the studs noggings and
plates to the light sends the into 'let's get out of here' mode to eat elsewhere in your
house. What's your is theirs and what's theirs is theirs. . Some people try to kill
them without exposing them to light... for me that's not good enough. Termites or
none...we are also looking at water saturation.
Now if we don't act fast they will hightail it further along. I killed them with fire (porta-gas) and
poison...poisoned left and right inside the walls leading to the bedrooms. I removed a panel
of the return wall in the bedroom to keep an eye out for the little bludgers...I was sure before
that I could hear them munching away at night.
I re-tiled the bath room floor after chiselling out all the tiles...quite a job and lazy tiler-bludgers
willjust tile over the existing tiles. That way I could control the waterproofing. I sealed with attractive
edging tilesthe rising edge the shower base which was below floor level. Nice view when scrubbing
ones feet!!..I paid a lot of attention to waterproofing.
While all that re-tiling was drying out...I drilled 50mm holes through the house plaster to inspect
other walls with a flexible fibre-optic and later sealed them with close fitting plastic lids.
I searched-for and found where the termites had accessed the wall...a truly lousy job by
the electrician back in 1968. I sealed that. I left the job for a couple of weeks to dry out. By the way
concrete eating termites have been discovered in USA some years ago. Great!..as if 'concrete cancer'
isn't bad enough.
I waited a year before redoing my bedroom wall...which I'd rebuilt up to a metre high...
That allowed my being able to see the shower area leakage if any. (notably on the the timber plate)
inside my wall.
The bathroom wall I'd rebuilt entirely with heavily poisoned timber...not commercial stuff which has
only a thin protection and when cracked as is common with rubbish timbers today the termites get
inside it. I sprayed poison and painted it also as far as I could along the inside of the walls adjoining
the bathroom. I didn't plaster that wall for a month...I wanted to monitor it for water...but had
turned the membrane up about ten inches. It would be some years before water found its way
under the times again...
I left the return wall in the bedroom for 2 years before re-plastering it (my bedroom!). The light
helped me monitor but also, that it was not 'termite-tourist' country.
I am writing all this to say...get inside your wall and see what's what....Re-plastering and repainting
is comparatively simple...but before attacking outside...have a good like INSIDE your worst wall and
go from there...the bathroom is a good spot. Kitchen and laundry are others but way secondary
to bathroom which is a very wet area and condensation seems natural...may be it is...but then
again maybe it's a tale-teller. Sure you can take-out a hundred and fifty bricks or more for a look.
It's your choice. If termites are not a problem my water suggestions are still valid.
Outside....
I dug around the slab and installed ag-drain after saturating the trench with poison.. Termites eat their
way through soil and roots to get to your restaurant. ..The presence of ants entering your wall could
mean they are farming termites... Opening interior walls will give an idea whence comes the water and
why it is sitting....where termites and water meet it will stay damp. Don't just go berserk with damp-
coursing before finding the actual problem....and don't think rising damp is a fairy tale. That said
the solution may not be bank-breaking and go like a bull at a gate attacking the slab and
bricks...or employing someone who does that. It could end up fixing nothing.
Now back to 'damp' and permanent cures...
If you dig say a foot below the slab and eighteen inches wide all around the (exterior) damp walls
..or all the external walls, heading in a slope to a 'get-away point' or a drain and fill it with river
sand.You don't need to go down metres or even a metre, normally ...just make a good job of
allowing water from under the slab to naturally run away.
Do that after using black plastic from (pushed-under under the slab edge and across
the interior of the trench with the edge laying out on the grass/dirt 12-24 inches whatever so
it doesn't get pulled away into the trench as you fill the trench....Run the sand in the
'u'-shape/square/oblong of the trench up to about 3 inches below ground level. Block the
runaway point.
Flood the trench to approximate 100% compaction of the sand (it will settle)..Sit an ag-drain
on it near to the bricks and then fill with river-sand to ground level, so it spills onto the
membrane edge, re-flood only the trenched area and then complete the leveling. That will
slow down any termite attack and when the job is finished allow surface water and water
under the slab to drain away.
When finished, remove any blockage you used to enable the trench to fill and sand
to settle. a lid-sealed plastic or galvanised container (as a sump) ...as used to interconnect
drains or conduits placed in the run-off low point might give an indication of effectiveness..
however it has to have an exit point also...there's no point in choking up the trench and
holding back the run-off. Put the sump base deep enough ...say six inches below the
bottom of the trench so as to have the exit at trench bottom level.
Of course the sand, nevertheless, will assist in evaporation
You can periodically poison the sand with termite killing chemical if you have termites
or could have Sand will not stop them but sand and poison will do so.
Moral
Ok you want to fix your problem...which is not fully defined for us...BUT...check first what
is actually happening inside your walls. and identify your actual 'problem.otherwise
a lot of 'useless' work can be done. and achieve nothing but heartache. Voila.
course isn't always on the slab...it could be a course or two higher...but it should be there nevertheless.
I'm giving a lot of experience in here...and instead of looking at other people's places I am referring
to my own experience. I have been on construction work for over 50 years so have a 'clue'.
Let's step back and get away from rushing at the seemingly obvious...Get away from the slab and
damp course issues for a while. Let's think about construction work.
Your brick looks hard...so damp would be difficult to permeate and difficult to dry out. Using gas
heaters is not a good idea. The surface damp might dry but condensation recurs and the brick is
still damp inside. The worst jobs can be seen in France...painting sandstone with enamels and
concreting walls where there never was any damp protection. The natural drying of the
stone/sandstone is inhibited
Painting brick which gets damp ensures drying-out is harder than if bare.
If there is no damp course you can fit it and it might be the cure...but don't dive into it. ...you
are fortunate in this way...only one layer of mortar has to be cut out for the damp course to
be fitted as you only have a single brick wall. You are not going to immediately find wet in
the house as you 'must' have a stud wall interior. I'll go into that later.
Sometimes a chainsaw with a tungsten blade is uses to progressively cut the mortar and install the
damp course or chemical barrier. It does not need to be right at the slab, one or two courses above is
ok...but let's think more about the situation...We have a slab which should be resting on impervious
black plastic at the time of the pour and reo /reo mesh laid on saddles...protecting the waterproofing
and spacing the reo to the correct position in the slab.
It's not uncommon for clays and rocks and rubbish of all kinds to be used as 'fill' to sit a slab upon..
The rock/glass/metal not uncommonly penetrates the plastic when the concreters are filling and
levelling. so...the waterproofing membrane may have been incompetently or 'carelessly installed
or damaged at the time...or never installed...or later eaten away.
Let's say the concrete is resting in a water course.(natural or man made) through back filling the site
for the slab ..why would the bricks get damp?..Concrete is porous but it should also be waterproofed
in the mix. The water should be running off or evaporating if the slab is surrounded by earth ...
and usually there is only 4-6 inches of concrete past the wall.
"Rising damp" is a reality but why would it be happening...work that out first....and that's the
essence of the solution.
Inside
That thought brings us to the other issue hinted-at by another contributor...Mortar left in the
wall and water coming downwards.. Mortar or cement flicked into the cavity or even dumped
into it.and hanging off the ties is easier than cleaning-up...but water has to get there to create
damp.. The brickies are long gone before you experience the problems and liquidation is a
run of the mill escape these days.
Some brickies are simply slobs...some are hopeless drunks even when on the job. I've seen
them cut bricks and besser, bricks ...with two men working on same wall...to meet a whole course
out..In one site they worked with a bottle of beer in hand and then left for two weeks to do their
marijuana harvest up in Queensland. That the job was across the road from the Harbord Hotel
was a bonus for them! On that job I've seen twists in pillars with 6 inches of cement slapped on
to make them look square... I was flabbergasted and the builder just let it pass. "Competent"?
You said 'single brick' wall.
Hang-on...Is it damp everywhere? or just somewhere?...is your problem condensation on the
plaster board during winter? or do we have a definite water ingress 'from outside or 'through
the slab' issue or are we barking up the wrong tree?
Your stud wall is likely tied to the brick and sitting on a bottom plate and with a top plate
mostly covering the small cavity. It could be good aged hardwood or pacific island rubbish.
The best timbers are smashed by demolishers when in my opinion by law they should be forced
to recover it...they charge a motza and could well and truly cover it in their costs. Tipping
fees are often high...but they double them anyway and they sell-off what they don't smash..
that's 'the cream'.When doing repairs look for sound old timber and treat is when low in the walls.
One possible trouble arising I will include is termites...they love soft timber...mmmm yummy!!.
..easy on the fangs too. They commonly, I was long ago told, eat alternate studs...so the
place doesn't collapse...like CV-19 our ingrained human stupidity...demonstrated effectively
24/7 in USA has us thinking it/they are not intelligent in their own environment. We are of course
'the master race'.
One of the places water enters walls is from leaking water pipe/pipes inside the stud wall...
and/or bathroom leakage...Water always leaches through the tile grout and leaks across the slab
or the membrane to the walls and saturates the bottom plate and then into the bricks.
The shower floor is first suspect for the major leakage problem if all water pipes are intact.
I found mine was just that....so here's the fix..
In my case I stripped-out the plaster in the bedroom adjacent the shower area..
the area was saturated. I stripped the plaster out of the whole wall under the bathroom
window (behind vanity ink and toilet) Bxxxxy termites everywhere!...in both walls but
only up to about two feet why eat leather when you can eat fillet steak) .
On termites....
Termites like dark...light sees them moving away so exposing the studs noggings and
plates to the light sends the into 'let's get out of here' mode to eat elsewhere in your
house. What's your is theirs and what's theirs is theirs. . Some people try to kill
them without exposing them to light... for me that's not good enough. Termites or
none...we are also looking at water saturation.
Now if we don't act fast they will hightail it further along. I killed them with fire (porta-gas) and
poison...poisoned left and right inside the walls leading to the bedrooms. I removed a panel
of the return wall in the bedroom to keep an eye out for the little bludgers...I was sure before
that I could hear them munching away at night.
I re-tiled the bath room floor after chiselling out all the tiles...quite a job and lazy tiler-bludgers
willjust tile over the existing tiles. That way I could control the waterproofing. I sealed with attractive
edging tilesthe rising edge the shower base which was below floor level. Nice view when scrubbing
ones feet!!..I paid a lot of attention to waterproofing.
While all that re-tiling was drying out...I drilled 50mm holes through the house plaster to inspect
other walls with a flexible fibre-optic and later sealed them with close fitting plastic lids.
I searched-for and found where the termites had accessed the wall...a truly lousy job by
the electrician back in 1968. I sealed that. I left the job for a couple of weeks to dry out. By the way
concrete eating termites have been discovered in USA some years ago. Great!..as if 'concrete cancer'
isn't bad enough.
I waited a year before redoing my bedroom wall...which I'd rebuilt up to a metre high...
That allowed my being able to see the shower area leakage if any. (notably on the the timber plate)
inside my wall.
The bathroom wall I'd rebuilt entirely with heavily poisoned timber...not commercial stuff which has
only a thin protection and when cracked as is common with rubbish timbers today the termites get
inside it. I sprayed poison and painted it also as far as I could along the inside of the walls adjoining
the bathroom. I didn't plaster that wall for a month...I wanted to monitor it for water...but had
turned the membrane up about ten inches. It would be some years before water found its way
under the times again...
I left the return wall in the bedroom for 2 years before re-plastering it (my bedroom!). The light
helped me monitor but also, that it was not 'termite-tourist' country.
I am writing all this to say...get inside your wall and see what's what....Re-plastering and repainting
is comparatively simple...but before attacking outside...have a good like INSIDE your worst wall and
go from there...the bathroom is a good spot. Kitchen and laundry are others but way secondary
to bathroom which is a very wet area and condensation seems natural...may be it is...but then
again maybe it's a tale-teller. Sure you can take-out a hundred and fifty bricks or more for a look.
It's your choice. If termites are not a problem my water suggestions are still valid.
Outside....
I dug around the slab and installed ag-drain after saturating the trench with poison.. Termites eat their
way through soil and roots to get to your restaurant. ..The presence of ants entering your wall could
mean they are farming termites... Opening interior walls will give an idea whence comes the water and
why it is sitting....where termites and water meet it will stay damp. Don't just go berserk with damp-
coursing before finding the actual problem....and don't think rising damp is a fairy tale. That said
the solution may not be bank-breaking and go like a bull at a gate attacking the slab and
bricks...or employing someone who does that. It could end up fixing nothing.
Now back to 'damp' and permanent cures...
If you dig say a foot below the slab and eighteen inches wide all around the (exterior) damp walls
..or all the external walls, heading in a slope to a 'get-away point' or a drain and fill it with river
sand.You don't need to go down metres or even a metre, normally ...just make a good job of
allowing water from under the slab to naturally run away.
Do that after using black plastic from (pushed-under under the slab edge and across
the interior of the trench with the edge laying out on the grass/dirt 12-24 inches whatever so
it doesn't get pulled away into the trench as you fill the trench....Run the sand in the
'u'-shape/square/oblong of the trench up to about 3 inches below ground level. Block the
runaway point.
Flood the trench to approximate 100% compaction of the sand (it will settle)..Sit an ag-drain
on it near to the bricks and then fill with river-sand to ground level, so it spills onto the
membrane edge, re-flood only the trenched area and then complete the leveling. That will
slow down any termite attack and when the job is finished allow surface water and water
under the slab to drain away.
When finished, remove any blockage you used to enable the trench to fill and sand
to settle. a lid-sealed plastic or galvanised container (as a sump) ...as used to interconnect
drains or conduits placed in the run-off low point might give an indication of effectiveness..
however it has to have an exit point also...there's no point in choking up the trench and
holding back the run-off. Put the sump base deep enough ...say six inches below the
bottom of the trench so as to have the exit at trench bottom level.
Of course the sand, nevertheless, will assist in evaporation
You can periodically poison the sand with termite killing chemical if you have termites
or could have Sand will not stop them but sand and poison will do so.
Moral
Ok you want to fix your problem...which is not fully defined for us...BUT...check first what
is actually happening inside your walls. and identify your actual 'problem.otherwise
a lot of 'useless' work can be done. and achieve nothing but heartache. Voila.
Last edited:
Lons
Established Member
Jack
That was an interesting read about what goes on over the pond, thanks for that but most of it has no relevance whatsoever to the problem in hand.
* It's a half brick wall so no cavity to be bridged with mortar.
* There are no stud walls or timber so rot and insect damage is not applicable.
* The damp is coming through an external brick wall that has a thick concrete slab butting against it and directing water against the wall.
* There is no indication of any damp origination from under the slab, the other walls are dry.
The above conclusions are of course from information given and not a personal inspection which I offered if the OP needs it but from that the solution is far less complicated and pretty obvious.
That was an interesting read about what goes on over the pond, thanks for that but most of it has no relevance whatsoever to the problem in hand.
* It's a half brick wall so no cavity to be bridged with mortar.
* There are no stud walls or timber so rot and insect damage is not applicable.
* The damp is coming through an external brick wall that has a thick concrete slab butting against it and directing water against the wall.
* There is no indication of any damp origination from under the slab, the other walls are dry.
The above conclusions are of course from information given and not a personal inspection which I offered if the OP needs it but from that the solution is far less complicated and pretty obvious.
