Hi. We have an old cottage - solid wall construction, bodged up by a developer some 20 years ago and in 2009 the subject of some renovation/remedial works.
There is a single storey lean-to on the end of the cottage. The end wall of this was badly bowed outwards and had a tension crackright down it. The builders took the render off and found there had originally been a doorway and that this had been filled in with concrete blockwork - not tied in at all to the brickwork on either side - hence the cracking. By the way we have no foundations at all - the cottage is justs built on clay...
The builders put in some 'strong boys' to hold everything up at gutter level (only about 2m above ground) and unpicked the middle section of the wall ie leaving the two corners in place. They put in a bit of a footing - only about 30cm - and then rebuilt the wall tying it in to the brickwork on either side and incorporating a 9" dpc. It was then meshed with stainless steel expanded metal lath and rendered. We used Sike 1 on the outside for the bottom 15" or so.
We had a chemical dpc done around all of the old part of the building - when they came to the lean-to, they came round the corner and perhaps 8" beyond where the physical dpc had been installed - so as to give an overlap. The internal walls were floated with a salt resistant mix and then skimmed.
This was all done in perhaps August.
In November I moved a piece of 8' x 4' plywood and some plasterboard that had been leaning against the end wall for perhaps some six weeks.
Behind, the wall was wet - not running wet but so wet that if you put your hand against it it came away wet. It had black and white mould on the wall and all over the plywood.
Obviously I moved the wood and the plasterboard and the wall - at least on the surface - dried out.
However, I later left a piece of floor boarding (8") standing vertically on edge some 6" clear of the wall and - what a surprise - the bottom few inches of the wall showed signs of mould and wet again.
Now, the company who did the chemical damp proofing say it is probably just the fact that the render takes some time to dry out.
The builder thinks that when we paved outside we have come up above the level at which he fitted the physical dpc - this is just possibly right. He wants to strip the bottom few inches of render off the inside and bottle in some chemical into the revealed mortar joint along the section that he rebuilt.
Does this sound like a good idea - do we let him do it on the basis that it probably won't do any harm even if it doesn't do any good?
Sorry for the long story - any input woulb be much appreciated.
Thanks.
There is a single storey lean-to on the end of the cottage. The end wall of this was badly bowed outwards and had a tension crackright down it. The builders took the render off and found there had originally been a doorway and that this had been filled in with concrete blockwork - not tied in at all to the brickwork on either side - hence the cracking. By the way we have no foundations at all - the cottage is justs built on clay...
The builders put in some 'strong boys' to hold everything up at gutter level (only about 2m above ground) and unpicked the middle section of the wall ie leaving the two corners in place. They put in a bit of a footing - only about 30cm - and then rebuilt the wall tying it in to the brickwork on either side and incorporating a 9" dpc. It was then meshed with stainless steel expanded metal lath and rendered. We used Sike 1 on the outside for the bottom 15" or so.
We had a chemical dpc done around all of the old part of the building - when they came to the lean-to, they came round the corner and perhaps 8" beyond where the physical dpc had been installed - so as to give an overlap. The internal walls were floated with a salt resistant mix and then skimmed.
This was all done in perhaps August.
In November I moved a piece of 8' x 4' plywood and some plasterboard that had been leaning against the end wall for perhaps some six weeks.
Behind, the wall was wet - not running wet but so wet that if you put your hand against it it came away wet. It had black and white mould on the wall and all over the plywood.
Obviously I moved the wood and the plasterboard and the wall - at least on the surface - dried out.
However, I later left a piece of floor boarding (8") standing vertically on edge some 6" clear of the wall and - what a surprise - the bottom few inches of the wall showed signs of mould and wet again.
Now, the company who did the chemical damp proofing say it is probably just the fact that the render takes some time to dry out.
The builder thinks that when we paved outside we have come up above the level at which he fitted the physical dpc - this is just possibly right. He wants to strip the bottom few inches of render off the inside and bottle in some chemical into the revealed mortar joint along the section that he rebuilt.
Does this sound like a good idea - do we let him do it on the basis that it probably won't do any harm even if it doesn't do any good?
Sorry for the long story - any input woulb be much appreciated.
Thanks.
