old load bearing wall removal - was it done right?

[robertoi]

Hi,

My kitchen previously had a load bearing wall across one end of it, which separated the old kitchen from the outside toilet/ coal hole. This was removed about 7 years ago by the previoys owner. Whilst ripping out the old floor in there the last few days, I have noticed that there is a distinct join between the two separate areas of concrete floor, where I guess they simply poured a new screed into the extended area. This join line had some obvious dampness in it.

On further examination, I found that some areas of concrete could be pulled up, only to find the foundattions of the old wall sitting right underneath it (literally a few cms from floor level), which is causing the patches of damp.

Is it normal to leave the wall foundations in place after removing a load bearing wall? Is the proximity of the damp bricks to the screed above likely to cause serious problems in future?

I am intending to lay a new liquid dpm over a self levelling acrylic screed in the next few days, after repairing the areas of concrete I pulled out with a waterproof cement? Does this sound sensible? Or are the risks great enough that I should rip out the old foundations and lay a new screed at that end of the room (I really dont want to do this!)

THanks,
Rob

 

[macca71]

It sounds to me that the wall was removed to just below the original floor level and the gap was then filled with concrete. For the job to be done up to buildings regs you should have a poly membrane covering all soil and lapping up the wall to the finished screed height, it should also lap approx 4" onto membrane (if there is one) where it joins the other floor. Then lay 50mm insulation on top (celotex) of that with more poly membrane on top. This seals your insulation in a poly sandwich to stop concrete eating away at it in a few years time. Then finish with 75mm of screed. You also need to check if an RSJ or concrete lintel was used to carry the wall above and not a length of timber! The liquid membrane will only work if the area to be covered is below your dpc on the outside brickwork, if it is make sure you cover the wall up and just past your dpc level.[/b]

 

[robertoi]

Thanks for the info - 99% sure there is an RSJ, its in a bloody big box running across the ceiling.

Pretty sure there is no insulation in the new bit of floor, but its only about 2 sq metres, and the rest of the room has the original concrete floor which is about 100 years old.

THe floor construction of the extended area is a bit wierd, there is a DPM under some of it, as I can see the edges at the interface with the wall, but I cant see any at the point where the old wall foundations are. Think Im going to leave it and forget I ever saw it, just do the levelling etc as planned.

Thanks again

 

[robertoi]

BTW - is it pretty common practise to leave the wall foundations in place ina modification such as this? I'd have thought it was more sensible to remove it completely, if its not offering any lateral support.

THe guys who did these modifications were (to my knowledge) total idiots btw.

 

[macca71]

They should of removed the brickwork to the new dig level then laid the poly over it so that the old wall was below your new floor. I did forget to mention a few inches of stone on top of the soil before your poly and insulation if you did decide to do the job up to regs.
Good luck.