Workshop question

[rkchapman]

I've recently moved back from Florida to rural Worcestershire, and want to start setting up a workshop in an old hen-house that is in the garden.

The shed is a reasonable size, maybe 10 metres by 5, and has a concrete slab floor (somewhat cracked), a wooden frame, wooden tongue-and-groove walls and new corrugated metal sheets on the roof. It is fairly riddled with woodworm though we had it sprayed when we first moved in.

It's usable (and used) as a workshop already, and I have a collection of machinery in there mostly brought back from the USA. However it is cold, drafty and damp (well, wet) which makes me suspect that my machinery won't last too long unless I do something about it.

Short of tearing it down and rebuilding (which I would rather avoid for all sorts of reasons), I was wondering what I could do to make it a little more hospitable to my tools (and myself)... and what I can do to protect my tools from rusting away in the meantime.

I think the damp comes from 2 main sources - up through the concrete (especially where cracked), and under the wooden walls (largely rotten at the bottom). There are gutters on the roof that drain into water butts at either side, but they tend to overflow and the water then floods under the wall into the shed.

I was thinking that I should build a wooden floor over the slab (presumably with some form of dampproof membrane between them) but there's another problem there in that the existing headroom is barely adequate. I suspect I'll end up replacing (piecemeal) the timber frame so perhaps I could push the roof a little higher as I do so...

So, with that lengthy introduction, I guess the question is what would you do?

 

[PowerTool]

Hello Richard,and welcome to the forum

I think what I would do is :-

1) Sort out the rainwater problem - find some way to divert it away from the shed,or build a soakaway.
2) Replace as much of the rotten timber as possible.
3) Fill cracks in the concrete floor,and paint it with some proper floor paint,to try and give it a waterproof surface (if you can't stop water rising through the concrete,at least stop it getting onto the floor)
4) Look at some form of heating and insulation

No.3 is obviously only a short-term solution,and the ideal long-term thing would be to rebuild it.

Hope this helps

Andrew

 

[suprasport]

Hi and welcome to the forum,
in respect of the floor you have 3 choices under the circumstances and short of ripping up the concrete
1 is as you mentioned with a wooden floor but if the concrete is flat enough you would get away with something like 2x2 if it was very well packed at say 6-8" intervals (very time consuming) and 22mm tongue and groove chipboard (moisture resistant) not ideal but it would work
or you could put a damp proof membrane over it and a dry mix of grit sand and cement about 1" thick over that, tamped down and a very light spray of water and then with the chipboard or ply on that, it does work and will solve the problems.
or follow powertools advice but put down 3 or 4 bags of self levelling compound down (only 5mm at a time) that will cost £30 to £40 before you paint the floor and you will have a lovely flat surface.
hope this helps.

 

[tim]

Welcome to the forum.

Personally, I would bite the bullet and start again. You have water coming in through the cracked floor and under the rotted walls. The T&G is unlikely insulated and corrugated roofing is top notch for being too cold in winter and too hot in summer. If the walls are largely rotted at the bottom then it may be worth looking at the structural integrity of the building.

Once you get your tools in place and realise that you still have damp or cold probs, you'll be very unwilling to move them all out again and it'll make your woodworking experience a lot less pleasant.

Its also rather difficult to repair in a room full of kit plus obviously water and electrics aren't clever bedfellows.

I reckon in the long run it will probably cost you less and make the whole thing less miserable. Don't know when you got back but the winters in these here parts can be a touch damp and grim esp cf Florida.

Don't think of this as a chore - think of it as the chance to build a fab new workshop which will give many years of pleasure and allow you to turn out high quality items that will appease SWMBO with all the time spent on the workshop. :wink: :lol:

Cheers

Tim

PS whereabouts in Florida and whereabouts in Worcestershire?

 

[OLD]

What ever happens you need to get the hen house dry so low cost work :-sort out the gutters get the rain caught and taken away. Is the surrounding ground to high allowing the rain to splash the structure (could be the source of rotting walls)and also make floor wet, dig it out or dig a channel profiled to take water away and fill with gravel if there is a bad ground water problem lay a porous pipe drain in the gravel . The floor cracks should be raked out and filled use SBR bond as a additive to repair mix and read up on its uses as its a waterproofer and its possible use in a new waterproof screed (5litre £13 toolstation).
While the building is drying and you are repairing the walls look at the roof if the sheets can be removed and replaced in order to raise the roof you could use them again but you get lots of condensation on cold steel and if reused should be sprayed with insulating foam which could also be considered for the walls .
If the above plus proofing of floor is ok you can lay chipboard on the floor and start woodworking.

 

[rkchapman]

1) Sort out the rainwater problem - find some way to divert it away from the shed,or build a soakaway.

Working on it, but my temporary solution (attach a hose leading down the garden and open the tap) keeps getting blocked.

3) Fill cracks in the concrete floor,and paint it with some proper floor paint,to try and give it a waterproof surface (if you can't stop water rising through the concrete,at least stop it getting onto the floor)

What should I fill the cracks with? I'm happy to paint the floor but I'm not sure it will stick unless I can solve the damp first.

you could put a damp proof membrane over it and a dry mix of grit sand and cement about 1" thick over that, tamped down and a very light spray of water and then with the chipboard or ply on that, it does work and will solve the problems.

By damp-proof membrane here are we talking about basically a sheet of polythene, or something more sophisticated? Also is it possible to do something like this on a portion of the floor at a time - for example, is it possible to join the DPM or is it important for it to be a single sheet

or follow powertools advice but put down 3 or 4 bags of self levelling compound down (only 5mm at a time) that will cost £30 to £40 before you paint the floor and you will have a lovely flat surface.

I like the sound of that, but will the damp rising through the cracked concrete cause issues?

Personally, I would bite the bullet and start again. You have water coming in through the cracked floor and under the rotted walls. The T&G is unlikely insulated and corrugated roofing is top notch for being too cold in winter and too hot in summer. If the walls are largely rotted at the bottom then it may be worth looking at the structural integrity of the building.

All true - there is no insulation at all,, and there are certainly some beams that are cracked at knots in the wood...

Once you get your tools in place and realise that you still have damp or cold probs, you'll be very unwilling to move them all out again and it'll make your woodworking experience a lot less pleasant.

Unfortunately I'm already at that point - my tools are in, and I have nowhere to move them out to. Hence the desire to repair in-situ if possible. I was hoping I might be able to do a "rolling rebuild" repairing a third of the building at a time to avoid having to move everything out.

Its also rather difficult to repair in a room full of kit plus obviously water and electrics aren't clever bedfellows.

I think once I sort out the rainwater then it should get badk to the "damp" rather than "wet" status... all the electrics are modern and have RCCD circuit breakers...

I reckon in the long run it will probably cost you less and make the whole thing less miserable. Don't know when you got back but the winters in these here parts can be a touch damp and grim esp cf Florida.

Ah, but the spring, summer and autumn make up for it!

Don't think of this as a chore - think of it as the chance to build a fab new workshop which will give many years of pleasure and allow you to turn out high quality items that will appease SWMBO with all the time spent on the workshop. :wink: :lol:

I would be tempted to rebuild, but there are a few things stopping me. Firstly is the issue of where to store my stuff in the meantime (if you think the shed is in poor condition, the garage is worse!). Secondly is the fact that one end of the shed has been converted to an office where I work every day - that part IS insulated, double-glazed, and dry (thanks to both a liquid and a polythene DPC under the laminate floor). Finally, it's in a conservation area so I have to be careful what I do without appropriate approvals...

PS whereabouts in Florida and whereabouts in Worcestershire?

Boca Raton, and Bromsgrove

Thanks everyone for taking the time to reply.

 

[suprasport]

the membrane is called visqueen and sold in large rolls at any builders yard it is a thick plastic sheet. it can be joined.

doing it with the the self leveller and then painting the surface will be ok as the paint itself is water resistant and the damp shouldn't crack the leveller if enough is applied (in stages) but it isn't a certainty

one more option is to put the visqueen down and then screed the floor ( a wet mix of grit sand and cement) laid 2" thick and then if the surface isnt quite upto scratch then put the leveller on that. you could get away with this in 1/3rd sections and it is the better option but much more difficult to get right.

It really depends how much you want to get involved and spend.

 

[Adam]

By damp-proof membrane here are we talking about basically a sheet of polythene, or something more sophisticated? Also is it possible to do something like this on a portion of the floor at a time - for example, is it possible to join the DPM or is it important for it to be a single sheet

I've seen DPM joined by rolling an overlapping seam then taping it. I'm sure one a large build this must be done often, as you can't possible have large enough sheets to cover large areas.

Unfortunately I'm already at that point - my tools are in, and I have nowhere to move them out to. Hence the desire to repair in-situ if possible. I was hoping I might be able to do a "rolling rebuild" repairing a third of the building at a time to avoid having to move everything out.

Plan it for a week or two in the middle of summer, then pull everything out, chain it together or something similar, throw something over and get cracking, whilst its not raining! Leave some ventilation though, your tools might rust more under a sheet which accumulates moisture.

Just a thought at least!

Adam

 

[Shultzy]

Richard, whether you repair or rebuild the water/damp is always going to be the main problem. A few pics of the site might be more informative as to the best solution. OLD's solution of land drainage is spot on as it will stop 90% of the water getting to the slab.

Also welcome to the forum.

 

[rkchapman]

What ever happens you need to get the hen house dry so low cost work :-sort out the gutters get the rain caught and taken away. Is the surrounding ground to high allowing the rain to splash the structure (could be the source of rotting walls)and also make floor wet, dig it out or dig a channel profiled to take water away and fill with gravel if there is a bad ground water problem lay a porous pipe drain in the gravel . The floor cracks should be raked out and filled use SBR bond as a additive to repair mix and read up on its uses as its a waterproofer and its possible use in a new waterproof screed (5litre £13 toolstation).
While the building is drying and you are repairing the walls look at the roof if the sheets can be removed and replaced in order to raise the roof you could use them again but you get lots of condensation on cold steel and if reused should be sprayed with insulating foam which could also be considered for the walls .
If the above plus proofing of floor is ok you can lay chipboard on the floor and start woodworking.

The more I look at it the more I think that the overflowing water butt is the cause of 90% of the problem.

If I can put in a damp-proof membrane with chipboard on top without raising the floor level by more than an inch or so, I may be ok with headroom. The issue is not the height of the roof so much as the two cross-beams that support it - I will keep banging my head on them. If I could refix them (or replace them with new ones) slightly higher without compromising the strength, that would be ok - I don't know how to find out if that can be done though.

There is an old wooden roof that is mostly still there underneath the corrugated one. I was thinking I might remove it to cut down the weight, but it is also probably acting as insulation so might be better to leave it.

I wondered whether a dimpled damp-proof membrane such as the one at http://www.drywallandfloor.co.uk/orderm ... google.htm might make things easier for me, particularly bearing in mind that I want to work on part of the floor at a time without moving everything out. If I can patch an area, put down a few strips of dimpled membrane, put chipboard on top, then move some tools onto it while I do the next bit, it would solve a few headaches.

 

[rkchapman]

Richard, whether you repair or rebuild the water/damp is always going to be the main problem. A few pics of the site might be more informative as to the best solution. OLD's solution of land drainage is spot on as it will stop 90% of the water getting to the slab.

Also welcome to the forum.

I'll try to sort out some pictures of the site.

I think it is repairable - but I want to make sure anything I do makes it better rather than worse!

 

[billybuntus]

Hello,

I'm currently bulding a workshop and the surface of the concrete floor is not even close to being level.

However I can't build the concrete pad up any more than its current height (the highest un-even part of it) So I'm building the rest up to the same level with concrete. The height restriction is due to possible complaints from neighbours :roll:

My main problem with this is that I can't lay a Damp proof membrane (thick plastic sheeting).

So I've found another solution which is liquid DPC which I will paint over the concrete pad when the roof and walls are up then possibly put some self levelling compund over that (about 1") when finished.

I would certainly sort your drainage out first though and get the walls and roof watertight then get your damp proofing sorted then insulate the building.

Heres a link to the Liquid DPC, http://www.screwfix.com/app/sfd/cat/pro.jsp;jsessionid=YSOBLAIMETBDVCJO2C1SIIQ?ts=20181&id=29359

and the spec sheet for it

http://www.arconsupplies.co.uk/pdfs/protective_coatings/aquaseal hyprufe.pdf

Hope this helps.

 

[rkchapman]

Hello,
Heres a link to the Liquid DPC, http://www.screwfix.com/app/sfd/cat/pro.jsp;jsessionid=YSOBLAIMETBDVCJO2C1SIIQ?ts=20181&id=29359

and the spec sheet for it

http://www.arconsupplies.co.uk/pdfs/protective_coatings/aquaseal hyprufe.pdf

Hope this helps.

Certainly looks interesting, but the spec sheet suggests that there should be a 50mm screed on top of it - which I don't really think I can do. Would it be ok if I just laid chipboard on to I wonder.

I think in the office half of the shed (where I paid a floorer to put in a laminate floor) he used a self-leveller, then a liquid DPC of some sort (looked like an epoxy based one), then a poly sheet, then some cushioning foam underlay, then the laminate. Seems to work well but was not cheap, and the area is much smaller.

 

[billybuntus]

You can use it then lay a floor over it e.g. chipboard or whatever.

It will stay watertight if its not trodden all over.

It will most certainly be better than putting a new concrete pad in and DPM! no thanks!

 

[billybuntus]

You could use the hyprufe, poly sheet (cheap!) floor insulation (cheapish depending on type) and then lay cheapo laminate or chipboard.

 

[OLD]

The dimpled membrane would have to have a screed or it will be crushed on a floor so height problem.
Get the building dry then tape a sheet one sq metre of clear poly. to the floor a small amount of moisture trapped in a week and you can consider poly sheet and chipboard any more and it will need more work.
Pictures would be helpful.
Any one that draws plans should be capable of sorting the alteration of the collar beams and extra strengthening to give head height.
These sudjestions are for long term solutions if you just want to use it poly sheet and chipboard will give you a floor.

 

[Shultzy]

Richard, I've had another thought about repairing in sections. Have you thought about erecting new walls around the old ones. When each section (1/3 at a time) is built remove the internal walls and put up a new roof.

 

[rkchapman]

Richard, I've had another thought about repairing in sections. Have you thought about erecting new walls around the old ones. When each section (1/3 at a time) is built remove the internal walls and put up a new roof.

The walls are right at the edge of the slab, so I don't think that would work. I think I will probably rebuild a section of wall every so often until the whole lot is done...

 

[Shultzy]

Richard, If you have the room you could lay 300mm concrete foundations around the shed, and put the new walls on it. Remember if you rebuild in sections you won't be able to lay the cladding across the joins, thus compromising the structural integrity of the building.

 

[rkchapman]

Richard, If you have the room you could lay 300mm concrete foundations around the shed, and put the new walls on it. Remember if you rebuild in sections you won't be able to lay the cladding across the joins, thus compromising the structural integrity of the building.

I don't really have the room... I don't think the cladding at present is adding anything to the structural integrity of the building - it is tongue and groove timber running vertically...

Perhaps the trick will be to make the sections that I rebuild at one time large enough that the overlapping at the joins is not an issue (e.g. one wall at a time!)

As requested elsewhere, I have some pictures:

The whole shed - the near part is my office, the far end is where the tools will go. In the centre is the water butt that causes a lot of the problems.

A view from the opposite corner

An example of the rotting at the bottom of one wall. Actually this is probably about as bad as it gets, and it should be pretty trivial to replace this section of cladding.

One of the a-frame rafters that I will start banging my head on if I raise the floor. If I can replace the cross-member with something a bit higher up it would be nice... Anyone know enough engineering to know if that will be safe? You can also see the wooden ceiling that is still present underneath the corrugated one, which I am wondering about removing in order to reduce the weight (especially if that means I can modify the rafters....)

Detail of the base of the frame...

One of the cracks and surrounding damp patch in the floor.

Larger versions of the pictures are at http://www.pbase.com/richardkchapman/workshop