No DPC fitted before laying timber over bricks Damp can be a major issue in the home. Find answers to questions or post your own here.

[NP808]

Hi, first time here but hopefully someone can offer some advice.

I had a carpenter build a garden room frame back in September. Part of the timber frame sits on top of an old brick air raid shelter.
The shelter ceiling was too low so I had the concrete roof cut off to allow the frame to extend off the top of it.
The guy did a good job but it wasn't until he'd left that I realised he hadn't fitted a DPC below any of the horizontal lengths of timber across the top of the walls or the vertical timbers on the sides of the walls.
If I hadn't made sure we fitted a DPC to the floor of the shelter, that wouldn't have had one either.
The external building is finished for the most and wrapped in a breather membrane.

My questions are: Is there anything I can do about this? Is there a product (say, an expanding foam) that I could apply into the small gaps to prevent any potential rotting of timbers? Do I have any options or is it just not fixable? How should I protect the timbers from water and drafts - is that necessary if the building wrapped and will be eventually cladded?

A pic is attached. I can upload more if required.

Thanks,

Nick

[stoneyboy]

Hi np808,
I don’t think you need to do any remedial works (fitting DPC) to the timbers on top of the wall, damp is unlikely to be a problem this high up and it looks like treated timber has been used.
Possibly something you should address is where the floor joists are against the outside walls - there does not appear to be any DPC up the walls, the walls are very likely to suffer from damp at this level.
Regards S

[NP808]

Thanks for your response Stoneyboy, thats reassuring re the higher up timbers and yes, treated timber was used throughout. Re the lower timbers, you raise a good point. The timbers are 150mm off of the ground but I guess the contact with the wall is where the issue's could / would arise - correct?

[stoneyboy]

Hi np808,
It looks like you have solid walls so damp is bound to be higher at low levels. If you can, slide sections of DPC down between the joists and the walls, fold and pin the DPC on top of the joists.its not clear whether you have any air bricks in place but it’s worth adding a few just the keep the floor timbers dry.
Regards S