Extension blocking air bricks

[am3897]

Hi, we have had a rear extension across the back of our 1930s house. The front room and what would have been dining room have suspended floors. Hall and kitchen solid floors.

At the time we asked the builder if he was putting air flow through the extension as the original airbricks at the back would no longer be there. Asking several times he assured us each time it didn't need it.

Fast forward 2 winters later, we now have rising damp in the front room..survey has concluded due to air flow which we were expecting. Options are strip the walls that are showing signs and put a damp membrane against the wall and re plaster. This to me hides the problem but im no expert? He did said we could add vents into the dining room floor in front of thr new extension concrete base and put a Mori sub floor mechanical fan at the front of thr house to recreate the air flow. In time then re decorate the front room where we have the water line.

Having renovated this house 12 years ago I ideally don't want to be taking the plaster/board back off the walls

I am just looking for some thoughts on this please from people who know more than us! Also should the building inspector have picked this up?

Thanks all

 

[Ollyfp]

Yep, by building the extension in this way, your builder has interrupted the all-important flow of dry air that kept your floors and walls healthy for many years! I mean, that's why the vent was put there by the original builders!
I'm afraid that you've been fobbed off a bit, but let's not dwell on that. Let's focus on the remedy!
Is your original DPC intact? If not, you could use the 'dry rod' system to prevent the rising damp in walls that are accessible?
Also, you'll need to find a way of reintroducing the flow of air, unless you're thinking of replacing your old suspended floors with insulated concrete screed, which is a big job of course.
Anyway, good luck with it all!

 

[am3897]

Yep, by building the extension in this way, your builder has interrupted the all-important flow of dry air that kept your floors and walls healthy for many years! I mean, that's why the vent was put there by the original builders!
I'm afraid that you've been fobbed off a bit, but let's not dwell on that. Let's focus on the remedy!
Is your original DPC intact? If not, you could use the 'dry rod' system to prevent the rising damp in walls that are accessible?
Also, you'll need to find a way of reintroducing the flow of air, unless you're thinking of replacing your old suspended floors with insulated concrete screed, which is a big job of course.
Anyway, good luck with it all!

Yes I believe the DPC is intact. Didn't want to replace the floors as we have oak flooring throughout that ideally I didn't want to disturb. Thank you!

 

[Notch7]

Also should the building inspector have picked this up?

Yes

Asking several times he assured us each time it didn't need it.

It probably needed remedial work to be done at the builders expense and he was probably desperate for his next draw.

 

[am3897]

Yes



It probably needed remedial work to be done at the builders expense and he was probably desperate for his next draw.

Where would we stand with the building inspector not picking this up do you know? Would it be court action or is there another route?

 

[freddiemercurystwin]

No don't waste your time, there will be no redress there, in anycase you would have to sue the builder before bringing any claim against the inspector, there is unfortunately plenty of case law that shows inspectors, private or local authority cannot be held liable, as bonkers as that may seem https://www.stephens-scown.co.uk/co...ng-control-arent-liable-for-spotting-defects/

There were two recent threads with similar issues may be worth reading:

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There may be others if you use the search.