Please help me fix my cold and damp workshop

[Triggaaar]

If, as you yourself have already said, there is no overhang (to speak of) to the end of the roof where do you propose to protect the top of any render?

I don't know, good point, thanks. I'll have a look at what I can do.

Also, if the guttering fills the void then surely any leaves will settle in the guttering as there's no way for them to get past...

Yes I'd be happy with that (I can empty the leaves from the gutter), but I'm not sure it'll nicely fill the void, it'll probably partialy fill it.

 

[matt]

Alternatively I could put some sort of joint into the existing downpipes, like a strap on boss fitting.

I have a tiny issue though:
I've just been to check the size of the gap (and remove that half brick). The gap is bigger than I though, which is fine (I could even screw plastic guttering instead of aluminium). At the top it's about 4 inches. The bottom (between workshop and boundary wall) is now covered with leaves. I'll remove these with a pole, but my concern is if any leaves were to drop after my work is complete, getting them out again would be a nightmare. Maybe I just have to make my guttering affair prevent leaves dropping down the gap.

Agree re getting the guttering to block leaves falling down but I would also roll up some chicken wire to block all openings. It doesn't even need to be visible - can be pushed back from the face of the building leaving just a smaller area where leaves might accumulate but can easily be removed.

 

[TrimTheKing]

Also, if the guttering fills the void then surely any leaves will settle in the guttering as there's no way for them to get past...

Yes I'd be happy with that (I can empty the leaves from the gutter), but I'm not sure it'll nicely fill the void, it'll probably partialy fill it.

Then matt's solution of chicken wire will work here too. Fold some chicken wire around the guttering but fill in the gap between guttering edge and boundary wall. It is stiff so should bridge the gap fine and you can pick the leaves off the tope without it interfering with the rain run off or blockingthe downpipe if you don;t get out there to clear them for a couple of weeks.

 

[MikeG.]

I'm loath to get involved, but you don't want any moisture down in that cavity, whether from the workshop, or from the garden wall. If you are going to go for a gutter solution, it should also act as a flashing such that water landing on top of the garden wall doesn't end up running down the gap.

Mike

 

[Triggaaar]

Agree re getting the guttering to block leaves falling down but I would also roll up some chicken wire to block all openings.

Sound good, thanks.

I'm loath to get involved

Too late for that, you're in it up to your neck

you don't want any moisture down in that cavity, whether from the workshop, or from the garden wall. If you are going to go for a gutter solution, it should also act as a flashing such that water landing on top of the garden wall doesn't end up running down the gap.

I hadn't thought about water landing on the top of the wall. I am prepared to be wrong here, I realise you know more about these things than me, but it doesn't seem that bad. There is airflow around the building (although a gutter may effect that) and at the moment, with nothing at all stopping water going down the gap, there is no standing water in the building. There never has been. The walls can be damp to touch after heavy rain, so it needs fixing, but my feeling is that it could easily cope with a bit of water/moisture on the floor outside. I think small amounts of water should be able to soak into the grond.

 

[TrimTheKing]

I think small amounts of water should be able to soak into the grond.

Of course it should but you need to be mindful of the amount of mortar that fell out during the bricklaying and whether that has created a 'bridge' between the brickwork and the wall. If this has happened then the water will run down the wall and track in across the bridge.

If you can jab a broom handle in all the way down the gap and hit soil then happy days, but I am definitely in agreement with Mike, if it was me I would most certainly be looking to stop any excess water getting down there. You will only be sorry if you don't and once you have it filled with toys you get flooded out...

You seem a little reluctant, but I think the guttering solution is a very elegant solution and I would have already kicked off in this direction.

Don't take the chance, that's my advice.

 

[Triggaaar]

you need to be mindful of the amount of mortar that fell out during the bricklaying and whether that has created a 'bridge' between the brickwork and the wall

There's no bridge above dpc, but plenty below. The bricks below dpc will get drenched.

If you can jab a broom handle in all the way down the gap and hit soil then happy days

Certainly not soil, it will be the concrete foundation which go right up to the boundary wall, but where the two meet water will slowly drain away.

You seem a little reluctant, but I think the guttering solution is a very elegant solution and I would have already kicked off in this direction.

I'd prefer it didn't need it, but I have already kicked off. I only stated this thread 2 days ago, I've had 4 or 5 quotes on making the aluminium, I've got someone booked to do the rendering, and I'm now looking at just standard gutter (or 76mm) if they fit better.

I agree that if I don't do a good enough job I will be sorry. If I get the gutter sorted though, we will be talking about a small amount of water running onto the bricks below dpc, which I'd have thought is not a problem.

Thanks again for all the help.

 

[MikeG.]

I'm loath to get involved

Too late for that, you're in it up to your neck

PM Sent

 

[Triggaaar]

Too late for that, you're in it up to your neck

Just to be clear, that was not a serious comment. My build does not have any problems following any advice from anyone on this forum.

 

[trousers]

Triggaaar wrote:
Too late for that, you're in it up to your neck

Just to be clear, that was not a serious comment. My build does not have any problems following any advice from anyone on this forum.

I'm finding it hard to take you seriously Trig.
Maybe it's the intonation that messages get when written on a forum such as this, which don't truly reflect what the poster meant.
Mike is a truly helpful bloke and I'm very suprised that he's stayed with this thread as long as he has.

I just feel there's some background here which you're not telling us.
For example, what did your "architect" specify for damp proofing measures on this build, especially wrt the problem that has so far lasted 5 pages here?
If it's a problem to you, your first port of call should be to the "professional" you paid to specify this lot in the first place. And although you apparently did ask "some time back" nothing seems to have come of it.
So have your "professionals" given you the elbow, or is it the reverse?
The more I read it, the more I think there was no architect in the first place, and now you've got a problem you've come to a woodworking forum to help you out for free.
So if I'm wrong you can tell us all why you really went ahead with a scheme which anybody on this forum could have told you was going to be trouble, let alone an architect.

 

[Triggaaar]

I'm finding it hard to take you seriously Trig.

Mike is a truly helpful bloke and I'm very suprised that he's stayed with this thread as long as he has.

I'm aware that Mike is very knowledgable and helpful, he was trying to help me with this a couple of weeks ago, and I understand that you are also very helpful to people on this site. I am quite shocked by your reply and don't understand where this mistrust has come from (on the 5th page of this I made one light-hearted comment to Mike, that's all).

I just feel there's some background here which you're not telling us.

No there isn't. I am a bit offended that you are assuming I am lying, which I am not, but I do appreciate that a lot of nonsense gets splashed around the internet, and that you don't know that this isn't an example of that, so I'll try not to be too offended.

For example, what did your "architect" specify for damp proofing measures on this build, especially wrt the problem that has so far lasted 5 pages here?

The problem has lasted 5 pages because as Mike said, it's not necessarily an easy one to fix. I built what my architect specified, and building regs signed the plans off.

If it's a problem to you, your first port of call should be to the "professional" you paid to specify this lot in the first place. And although you apparently did ask "some time back" nothing seems to have come of it. So have your "professionals" given you the elbow, or is it the reverse?

Until posting on this thread I wasn't aware that their was a problem with the guest house part of the build (ie, it is totally dry etc). I also didn't believe that the problem with the workshop was that bad. I thought it was damp and needed fixing, and I thought I might get better ideas on here on how to fix it than my architect would have. So I've only spoken to the architect about the problem with the shed (I didn't ask them to design it as a workshop) and they suggested I could put Vandex or similar on the inside of the wall. I've since discussed rendering the top 3 feet and catching the water that drips off which they think is a good idea.

When designing the build I think my architect:
a) wanted to get me building regs approval
b) didn't care about my shed (I didn't ask them to) - although they specified a dpc for the shed, they didn't specify dpm (and when I say specify, I mean to get building regs approval, not that they recommended I didn't put in a dpm).
c) assumed I was more bothered about getting the maximum width from my shed than it being completely dry (I am bothered about the width, but had no idea the single skin wall would be so damp)
d) may have thought that the gap between the walls would not have been filled with concrete, and may have drained better.

The more I read it, the more I think there was no architect in the first place, and now you've got a problem you've come to a woodworking forum to help you out for free.

If I didn't have an architect I would have no problems asking the helpful people of this forum for free advice. I do have an architect, and I still think it's a good idea asking for some advice with my problem. My problem isn't that dis-similar to Dibs's workshop, where he built very close to a dry stone wall, and you recommended a product for him coat on his walls.

So if I'm wrong you can tell us all why you really went ahead with a scheme which anybody on this forum could have told you was going to be trouble, let alone an architect.

I'll send you a pm.

 

[matt]

That's that then... Can we get back to the more enjoyable challenge of helping solve the problem now rather than have what promised to be quite an interesting thread descend into futile finger pointing. The latter is quite boring.

----------------------------------------------- <- look, I've even drawn a line under it for everyone

 

[Triggaaar]

Well...

I fitted 4" gutter around the outside (joining existing downpipes), with an aluminium drip attached to the wall, which was then rendered. This appears to have done the trick as planned.

I've just emptied the workshop so I can insulate it, and I'd like some advice on that please.

Ceiling:
I plan to put some cuts in the roof breathable membrane, at the ridge, to help with ventilation. I then want to put about 170/200mm of rockwool type insulation between my ceiling joists, put a vapour barrier underneath, and then OSB.

Walls:
I don't want to lose any width, but I need to remove the cold wall to moisture condensing, so I was thinking of putting 1" battens on the walls (vertically) with some rigid insulation (maybe whatever's cheapest) either between the battens, or over them? and then OSB as the internal finish.

Hopefully I can use the same rigid insulation for the doors. I then need to put a fan at the back/top for some ventilation, paint the lot white, and hopefully that's it.

Any suggestions on whether that seems like a good plan will be appreciated

Thanks

 

[Lons]

Hi Trigg

I've read the thread with interest but like others I've been reluctant to comment as I too thought it "didn't seem quite right" and I didn't want to get involved.

I think you're a genuine guy looking for help and perhaps there was a breakdown in communication between you and your architect?

I'm puzzled by a few things:- :?

If the building was subject to building regs ( I assume you required planning approval as it was within 1 metre of your boundary), then the BI would have suggested your floor should not be laid without a DPM in place (and in some areas subject to a radon barrier). Lack of floor insulation I understand but was shortsighted for little extra expense.

Your architect should be shot IMO for failing to point out the dangers of building so close to a boundary wall and of the 100% certainty of water penetration through a single brick wall. Worse if subject to driven rain!

You've been offered good advice so I won't add to that but IMO unless you do stop the ingress on the outside, you will never solve the problem entirely. If you do batten the inside, you would need a membrane and there is a danger of your fixings rusting in the wet bricks.

ALL BRICKS ARE POROUS to a greater or lesser degree, which is why dense bricks or blocks are used below DPC and why cavity walls were designed so that water would dissipate harmlessly down the inner surface of the external leaf. That's why there must be cavity trays over windows and doors and why the cavity must not be bridged.
Rising damp is a very real problem and why dpm must be linked to and under the DPC which should be minimum 150mm above ground level!

I'm not trying to criticize - just explain so please take my comments constructively. I'm a builder btw

cheers

Bob

 

[Triggaaar]

Hi Bob, thanks for the reply

perhaps there was a breakdown in communication between you and your architect?

There hasn't been - honestly, I'd just say if there had.

I'm puzzled by a few things:- :?

If the building was subject to building regs ( I assume you required planning approval as it was within 1 metre of your boundary), then the BI would have suggested your floor should not be laid without a DPM in place (and in some areas subject to a radon barrier).

I have planning permission, and building regs. Most of the building was obviously spec'd with a DMP, got a DPM, and was all fine. This bit wasn't spec'd with a DPM because it's just a shed. It was spec'd with a DPC, and I put a DPM in anyway, but I didn't have too (building regs wouldn't care if a shed didn't have a DPM). I don't know what a radon barrier is.

Lack of floor insulation I understand but was shortsighted for little extra expense.

If I were starting from scratch and wanted an insulated floor in the shed I guess I'd need to have the foundations lower, and screed on top of jablite or something, but that seemed like a lot of effort at the time for what was intended to be a shed.

Your architect should be shot IMO for failing to point out the dangers of building so close to a boundary wall and of the 100% certainty of water penetration through a single brick wall. Worse if subject to driven rain!

Well I guess you're right, he should have forseen the problems and advised me.

You've been offered good advice so I won't add to that but IMO unless you do stop the ingress on the outside, you will never solve the problem entirely.

As far as I know, the problem has been stopped. Rendered the outside bit that was subject to driving rain, and added a gutter. Before I did that work, I never got any damp of any sort in the main building, and I only got it on the walls of the shed. Now I don't get any. I'm just wanting to get the inside insulation done.

If you do batten the inside, you would need a membrane and there is a danger of your fixings rusting in the wet bricks.

Well they're not wet any more - do I still need to use a membrane?

Rising damp is a very real problem and why dpm must be linked to and under the DPC which should be minimum 150mm above ground level!

My DPM and DPC seem to be doing their job ok.

Thanks

 

[Triggaaar]

Maybe I should start another thread, as my question is a bit lost in all this old info.

I think I'm about to order some sheets of 25mm celotex (or equivellant) for the walls. So, for my shed/workshop walls (which are dry) should I:
a) Just put the celotex straight on the wall, with OSB on top
b) Put 25mm battens on the wall, with the celotext in between the battens, then OSB on top
c) Put 19mm battens on the wall, and then celotex and OSB over the battens, giving me a 19mm gap between the celotex and walls?

Thanks

 

[Triggaaar]

Nobody know the best way to insulate a single (half) skin brick wall?

 

[Deejay]

Hello Trig

Try over on The Wood Haven and see if Mike Garnham replies

Cheers

Dave

 

[Triggaaar]

Thanks for the reply Dave.

I expect quite a few people here know the best way to do it, I'm sure I've read it before, but I can't seem to find the same situation with the search facility. I've got the gear arriving tomorrow, so unless I'm stopped in my tracks I'll be using 2" battens with 50mm insulation in between.

 

[tisdai]

Hi Triggaaar

I am having a similar problem, the difference with me is hat i have a Concrete Panelled Garage, that is single skinned as well, i sort of hijacked a current thread about it. The following was the end result, I am going to build an inner frame and just leave a small gap between the wall and the inner stud wall, the concrete on the inside of the garage i will be using a Liquid DPM on, might work for youafter you have sorted the outside of the wall out.

But remember to place a DPM or Plastic sheet between the inside board of the workshop and the studwork and insulaion. It was explained to me that the DPM will avoid any moisture from the workshop getting through and causing the insulation to get damp.

Ok think i got it right this time, here's hoping lol

ie;

Concrete Outer Wall with a liquid DPM applied, I want to stop water entering the garage
Space 2 inch / 1 inch
Vapour Barrier
Studwork & Insulation
Air Barrier / DPM or Platic Sheet ?
Boarding on inside of workshop space,

This is the actual thread it is in

https://www.ukworkshop.co.uk/forums/t-g- ... 62-15.html

Hope it helps in some way m8.

Cheers

Dave