Newly Rendered Wall Letting in Water Damp can be a major issue in the home. Find answers to questions or post your own here.

[Chris-J]

Hello all

First post here and I am really hoping someone can help me.

I've just had an external wall rendered on a shed I am having built. The render went on over a week ago and all seemed fine.

Recently we have had heavy rainfall and I have noticed there's quite a bit of wet coming through one of the external walls. The other three are bone dry; the one that's an issue is more exposed to weather conditions.

I don't know if the renderer used SBR, but I did notice he used a plastic bottle of something (can't recall the name) but I did notice it said 'Waterproofing' on it.

I don't have a clue. I fix pcs, so I haven't any idea what to do. I'll post some pics and perhaps someone would be kind enough to offer me advice.





The joints look a little too thick, but elsewhere the walls are dry so I'm not sure that's the issue (probably doesn't help though). I'm quite worried and was hoping I would be able to paint something over the render to help waterproof it.





The surface seems damper in places. This was after we'd had heavy rainfall for about two days. You can see where the fibreglass edging has come away due to the crazy heat we had this summer, but it's like that in two other places (I'll be fixing it soon) and it's bone dry there.

What options do I have other than having to take the render off that wall?

Thanks all.

[thedoctor]

Hi

On looking, it looks like possibly a roof leak so probably worth giving the roof area a really good going over just to check and make sure there's nothing causing the leak anywhere.

Also, check over the render very carefully for any cracks, no matter how small they may be. If you do find any, you will need to call back the guys that did it.

One option you may have is to coat the wall with someting like Thompsons Water Seal, following the instructions on the tin.

One downside to this will be that the wall will effectively be sealed and water tight e.g. non-breathable which may cause other issues don the line.

Hope this helps

[collectors]

Out of curiosity i notice the joists are running the length of the shed? I only ask as it unusual with joists normally going the shortest width & was just wondering where the gutters are?

[Chris-J]

Hi

On looking, it looks like possibly a roof leak so probably worth giving the roof area a really good going over just to check and make sure there's nothing causing the leak anywhere.

Also, check over the render very carefully for any cracks, no matter how small they may be. If you do find any, you will need to call back the guys that did it.

One option you may have is to coat the wall with someting like Thompsons Water Seal, following the instructions on the tin.

One downside to this will be that the wall will effectively be sealed and water tight e.g. non-breathable which may cause other issues don the line.

Hope this helps

Thank you very much for the reply.

The roof is newly constructed from fibreglass and I don't think it's leaking. At least it is bone dry underneath.

The renderer came up yesterday and said it was 'odd' it was doing that but that it will be ok once I seal/paint over it. Someone mentioned Tyrolean the other day as a possible sealent.

Thanks again for the advice.

[Chris-J]

There's a lip along the front and side edges and a gradient to the back of the roof. The guttering is at the back and it seems to be working as it should.

[thedoctor]

Hi

No worries - In terms of Tyrollean, essentially this is really just a form of render and often used to cover poor quality existing render or brickwork (more on this here: https://www.diydoctor.org.uk/projects/r ... nishes.htm)

It may be the case that a good couple of coats of paint will resolve the issue, but unfortunately this won’t be known until you’ve got it on the wall.

Just make sure you use a good quality exterior masonry paint that’s both breathable and waterproof if you do go down this route

Kind Regards

[Chris-J]

Hi

No worries - In terms of Tyrollean, essentially this is really just a form of render and often used to cover poor quality existing render or brickwork (more on this here: https://www.diydoctor.org.uk/projects/r ... nishes.htm)

It may be the case that a good couple of coats of paint will resolve the issue, but unfortunately this won’t be known until you’ve got it on the wall.

Just make sure you use a good quality exterior masonry paint that’s both breathable and waterproof if you do go down this route

Kind Regards

Thank you Doctor

Something by Sandtex or is there a better alternative?