Damp-proofing for new shed

[ningham67]

Hello,

I am planning to build my own shed - probably starting next Spring. The shed is intended to be more of an outside room, so will be insulated, and may well ultimately house an armchair and a beer fridge! I am happy enough with putting down an insulated, damp-proof concrete base.
I intend to build 3x2 framework walls. These will then be clad in plywood or similar, before finishing off with shiplap or similar

My main concern is to stop water soaking into the timber frame where the timber is secured to the concrete base. I am thinking that a solid plastic strip say 4 inches x 1 inch running under each timber wall would be a good solution to keeping the timber dry. I would then attach the framework to the concrete with the plastic strip sandwiched between the two.

Is this a good idea? Is there a better way to do this? Do such plastic strips exist, and if so where do I buy them?

Cheers

Neil

 

[Deluks]

Damp proof course, aka DPC. About £3 from your local builders merchant or other shop.

Lay 4" concrete base. Build up 2 courses of brickwork at the perimeter, dpc, damp proof membrane (polythene over the concrete ) and your timber frame on top of this. The frame won't move once you've clad it.

Lay some insulation on top of the polythene and board over with t&g chipboard.

 

[ningham67]

Thanks for that Deluks, but I really want to get away from having to build a brickwork wall base if I can.

I think that the regular rolls of DPC are too thin for what I want.
Have you seen anything like the plastic strip that I tried to describe?

The shed will have guttering on it for me to collect rainwater so that will help. Ideally I just want to stop any rain that hits the concrete base from soaking up into the frame.

 

[Deluks]

It's not soaking that's the problem, but splashing. That's why dpc in brickwork has to be 150mm up from the ground, so that any rain that lands only soaks the wall below it (speak of the devil it's tipping it down outside!)


If you intend to proceed with the frame at ground level then you should only build the concrete base to the same footprint as the structure, and lay a bed of pea shingle about 2 inches deep and 8 wide around the perimeter, to disperse rain splashes.

You could use synthetic decking boards to build on? But I'd defo go with the bricks.


How do you intend to stop water running under and into the inside? Cos it will.

 

[ningham67]

Thanks again for the reply. I have been away a few days so am only replying now.

Is there any particular brick that would be better for this job, and would a single skin of two courses be enough do you think?