Water pooling in DPC of timber frame

[octopods]

Currently building a timber frame extension that's sitting on block work. We have DPC that the frame sits on between the block and the frame but started seeing pooling of water coming through. We've got housewrap on and render boards right now. And have folded the DPC upwards Rain water is still getting through... Any thoughts on why this is happening? You can see the water pooling on the inside.

 

Could it be due to the DPC folding up on the external side? I heard that was regulations in the UK to have it fold up?

 

[Iceverge]

Zoom out please and take more pics. 

 

Is this the inside or outside, ground floor, first floor or flat roof. It's hard to tell unfortunately. 

 

A few drawings/sketches would help too. 

 

 

[octopods]

1 hour ago, Iceverge said:

Zoom out please and take more pics. 

 

Is this the inside or outside, ground floor, first floor or flat roof. It's hard to tell unfortunately. 

 

A few drawings/sketches would help too. 

 

 

 

Ah sorry, this is internally. The water is coming in from external which isn't currently rendered. We have render carrier boards on at the moment but not been basecoat and meshed yet.

The build is a timber frame on top of a block extension. I've got an old photo of one side before it was boarded. The other side we have rendered between the bridge of the block extension and the timber frame's carrier boards.

 

I think I may know now where the water is getting in from. We had temporary gutters in place and the water is getting behind the gutter and running down the wall and through the gaps around the window. I don't think we have any window tape seal from the looks of it and it must be getting through there. That seem plausible?

 

Edited March 26, 2023 by octopods

[octopods]

Forgot to attach photos. Last photo was before we render boarded

 

Edited March 26, 2023 by octopods

[octopods]

I can see water between the housewrap and render boards when I look through a gap in the window. I think the water is getting through, trapping between the render bridge between the timber frame and the block extension it sits on.

[Iceverge]

1 hour ago, octopods said:

We have render carrier boards on at the moment but not been basecoat and meshed yet.

 

Hold fire on the render until this is sorted. You may need to remove the boards. 

 

You need to have a 100% weather proof later over the timber frame before proceeding. The outer layer of render board is only really to deal with 99% of water. The one under this (tyvek house wrap) needs to deal with the full 100%. 

 

 

Do you currently have windows and/or a roof on? 

 

Has the tyvek been properly lapped at all junctions? Did you tape it? 

 

 

17 minutes ago, octopods said:

trapping between the render bridge between the timber frame and the block extension it sits on.

 

This sounds strange. The vented cavity behind the render board should be able to freely drain away in case of any water ingress. 

 

It certainly shouldn't pool behind it . Can you do a quick cross section sketch of what has been built please?

[octopods]

4 hours ago, Iceverge said:

 

Hold fire on the render until this is sorted. You may need to remove the boards. 

 

You need to have a 100% weather proof later over the timber frame before proceeding. The outer layer of render board is only really to deal with 99% of water. The one under this (tyvek house wrap) needs to deal with the full 100%. 

 

 

Do you currently have windows and/or a roof on? 

 

Has the tyvek been properly lapped at all junctions? Did you tape it? 

 

 

 

This sounds strange. The vented cavity behind the render board should be able to freely drain away in case of any water ingress. 

 

It certainly shouldn't pool behind it . Can you do a quick cross section sketch of what has been built please?

 

Tyvek has been properly overlapped but no tape. I can't imagine the water is getting in between the overlaps as it's lapping by quite a bit anyway. I don't think any water is behind the housewrap itself but it's water between that and the render carrier board instead? We currently have no proper gutter so rain is running down the face.

 

Heres a very rough sketch (apologies!) of what we have so far. I do wonder if the bridge between the existing extension and the render board is whats causing all the issues. Should there be a vent at the bottom of the timber frame rather than having it rendered between so the water can drain if any enters?

 

[octopods]

How would I best create some sort of drainage between the second storey rendered timber frame and the lower storey block rendered extension?

[ETC]

The sketch doesn’t seem to tie up with the photograph. The battens in the photograph project over the blockwork below. Or have I missed something?

[ETC]

In the sketch any water hitting the house wrap will come into the extension.

[octopods]

6 minutes ago, ETC said:

The sketch doesn’t seem to tie up with the photograph. The battens in the photograph project over the blockwork below. Or have I missed something?

 

Sorry the previous photos are old and my sketch is wild inaccurate with the sizing/projection of things. The one of the outside we hadn't battened or render boarded it yet. The battens do slightly project over the brick work but if you see below that, the existing extension is rendered so it actually sits inline with the old rendered building once the render boards are on. I'll try take a photo tomorrow when it's light and the tarp has been taken down.

Edited March 26, 2023 by octopods

[octopods]

It's probably more like so (minus the mis labeled osb)

Edited March 26, 2023 by octopods

[Haylingbilly]

I think you also need to consider how you get ventilation behind the render boards as failure to do that will cause other issues. When I had similar issues the render and render board supplier was able to help with suggested detailing so would suggest trying them.

 

[octopods]

2 hours ago, Andy brown said:

I think you also need to consider how you get ventilation behind the render boards as failure to do that will cause other issues. When I had similar issues the render and render board supplier was able to help with suggested detailing so would suggest trying them.

 

 

We've got the top ventilation from no butting the render boards too high up and the roof soffit has some vents but yeah the bottom of the wall will need address to help vent from bottom and drain too. Need to work out how we solve that as we have an existing render wall below too. Good shout with asking our render supplier, we went with EWI.

[Haylingbilly]

5 hours ago, octopods said:

 

We've got the top ventilation from no butting the render boards too high up and the roof soffit has some vents but yeah the bottom of the wall will need address to help vent from bottom and drain too. Need to work out how we solve that as we have an existing render wall below too. Good shout with asking our render supplier, we went with EWI.

That's who I went with and they were brilliant.