T&G ship lap cladding question

[carpenter1]

is it leaking on the provalling wind side?

 

did you clad on to stud work, or did you have stud work covered by ply or sterling board?

[carpenter1]

which way have you got the boards up?

i have know people put them the wrong way up

[blades]

Not the new shed than.

From what you have said I am presuming that there is no breathable membrane behind the cladding. On a building like that I would have expected one. Is it much water or just a little dribble? You may always get a small amount through where the ends meet. This would not really mean anything on an open barn or shed but on a building like that I can see your problem. I would apply more of the same finish paying special attention on the joins and hope for the best. I know you are pretty sure it is not the roof but is there any chance rain is blowing under the edge flashing and then dribbling down inside. If it was that it is an easy fix with a line of mastic tape applied between the last ridge of the roofing sheet and the underside of the flashing.

 

Thanks.... No not the new shed.... It seems like a small amount seeping through the joins.... The inside wood is wet along the joins as opposed to running water.

 

As I mentioned the roof is timber sarking on to the trusses, then roof shield membrane on top of the sarking going over the end roof edges.... Purlins on top of the membrane and roofing tin on top of the purlins.... 2" air gap between the tin and membrane so zero condensation forming on the underside of the tin.

 

I feel you are right... I'll try another couple of coats as soon as weather allows.

 

Cheers mate

Edited February 3, 2013 by blades

[blades]

Are you absolutely certain its not condensation on the inside of the roof which is then running down? Does it show wet from top to bottom, and across the full width, or is it localised?

 

If you're prepared to overcoat afterwards, you could try a bottle of food colouring or water-based ink, applied strategically (e.g. on the outsides where you think water is coming through) and see if you get traces on the inside. This will give clear indication as to where the water is penetrating.

 

Alec

 

I'm sure it's not condensation.... Good idea re the water based ink.... At for that

[blades]

A couple of extra pics.... I hope you can see here how it looks as if the water just seeps in at the joins??

 

And a pic of the roof... all looks dry

[Graham S]

Was that piece of roof wet when erected if so it could be drying out , funny how how it's only on the one piece , the tongue could be damaged .

[Graham S]

My mistake it's on more than the one .

[muttley9050]

If all shiplap is fitted properly and nice and tight, then i would guess that when you coated the outside you trapped some moisture in there, if this is the case it has no where to go except inside, should remedy itself by the end of summer. Its hard to give another hypothesis without seeing the bulding or at least external photos of the problem elevation. Looks to me like a nicely built barn.

James