Hello there, i hope you guys can help me.
I’ll try to give you as much info that i can, but sorry if i go on a bit !!
I’m a general builder, and I’ve been dealing with some damp issues in an old cottage ( the usual stuff damp walls and floor etc).
There’s a solid oak floor laid to the lounge/diner, this had a section that had cupped quite badly this section is 4 boards ( 150 mm wide by 22 mm thick boards ) wide and 7.5 m long but these 4 boards are split in the middle with a nib of wall, so there are 4 boards either side of the wall 3.6 on each run, if that makes sense!
There was no expansion gap to this edge, in fact the boards were imbedded into the plaster and render, plus they were starting to go rotten on this edge ( you could push a knife into them).
My first thoughts were there’s no expansion gap and the wood swelling has caused this heaving.
I removed the skirting and these boards, they where stuck down to the concrete slab with a trowel on adhesive, when i lifted the boards there were areas that were wet, drops of water to the under side of boards in isolated areas, it looked like they were trapped between the adhesive and the timber.
When the damaged boards came up it lifted areas of the concrete slab, so i patched these up, i then blackjacked any holes behind the skirting that needed it and patched them up too. When this was all dry i blackjacked the exposed slab and up to the top of the skirting line.
This outside wall is a solid 9 inch wall thats been injected, but on the inside this is at the point where the wall meets the slab and the oak floor. The walls above the floor in this area are showing no signs of damp so I’m assuming that the damp injection that had been done some years ago is doing its job.
I couldn’t find any kind of flooring to match this off the shelf so i had to get some cut for me.
I got 10 x 3.6 m lengths of T & G canadian white oak, I fitted these in full lengths either side of the nib of wall. i had to get an extra one for each side because where the existing boards had been left for a while the next one along had started to curl up. I left an expansion gap around the edge, refitted skirting, then stained and varnished etc, i couldn’t believe that i managed to actually match up the colour by building up layers of stain. All was done, everyone happy- until i got a call a week later.
When i saw it i couldn’t believe it, it was worse than before! it had cupped really badly along the same place as last time heaving the two boards where they join and all the other new boards had a very slight cupping to them.
After looking at this forum i realise that i made some mistakes, i didn’t leave the boards to climatise in the room, and that i didn’t use the same adhesive , i just used a no more nails equivalent.
There is no DPM or insulation under the slab plus the internal floor level is below the outside ground level. Blackjacking the floor and skirting area should stop any damp coming through i would hope but I’m not sure about the line from the blackjack to the existing adhesive.
Questions : Would the water drops in between the adhesive and boards be condensation ? Could this return?
If i re-lay this section with proper adhesive and leaving boards in room for the week, is it likely to do the same again ?
The floor is glued down and there is no expansion that i can see to any other wall but this was the only area that had cupped. Do i need to go around the whole floor and cut an expansion gap?
I didn’t think that it was correct to lay this floor with no DPM or insulation etc. Was this floor laid correctly in the first place?
Am i totally to blame for it cupping the second time, or would this of happened down the line, just a little slower ?
I really want to sort this out for the customer and to give her the best information and advice i can and i’d like to thank you guys in advance for any help you can give me.
I’ll try to give you as much info that i can, but sorry if i go on a bit !!
I’m a general builder, and I’ve been dealing with some damp issues in an old cottage ( the usual stuff damp walls and floor etc).
There’s a solid oak floor laid to the lounge/diner, this had a section that had cupped quite badly this section is 4 boards ( 150 mm wide by 22 mm thick boards ) wide and 7.5 m long but these 4 boards are split in the middle with a nib of wall, so there are 4 boards either side of the wall 3.6 on each run, if that makes sense!
There was no expansion gap to this edge, in fact the boards were imbedded into the plaster and render, plus they were starting to go rotten on this edge ( you could push a knife into them).
My first thoughts were there’s no expansion gap and the wood swelling has caused this heaving.
I removed the skirting and these boards, they where stuck down to the concrete slab with a trowel on adhesive, when i lifted the boards there were areas that were wet, drops of water to the under side of boards in isolated areas, it looked like they were trapped between the adhesive and the timber.
When the damaged boards came up it lifted areas of the concrete slab, so i patched these up, i then blackjacked any holes behind the skirting that needed it and patched them up too. When this was all dry i blackjacked the exposed slab and up to the top of the skirting line.
This outside wall is a solid 9 inch wall thats been injected, but on the inside this is at the point where the wall meets the slab and the oak floor. The walls above the floor in this area are showing no signs of damp so I’m assuming that the damp injection that had been done some years ago is doing its job.
I couldn’t find any kind of flooring to match this off the shelf so i had to get some cut for me.
I got 10 x 3.6 m lengths of T & G canadian white oak, I fitted these in full lengths either side of the nib of wall. i had to get an extra one for each side because where the existing boards had been left for a while the next one along had started to curl up. I left an expansion gap around the edge, refitted skirting, then stained and varnished etc, i couldn’t believe that i managed to actually match up the colour by building up layers of stain. All was done, everyone happy- until i got a call a week later.
When i saw it i couldn’t believe it, it was worse than before! it had cupped really badly along the same place as last time heaving the two boards where they join and all the other new boards had a very slight cupping to them.
After looking at this forum i realise that i made some mistakes, i didn’t leave the boards to climatise in the room, and that i didn’t use the same adhesive , i just used a no more nails equivalent.
There is no DPM or insulation under the slab plus the internal floor level is below the outside ground level. Blackjacking the floor and skirting area should stop any damp coming through i would hope but I’m not sure about the line from the blackjack to the existing adhesive.
Questions : Would the water drops in between the adhesive and boards be condensation ? Could this return?
If i re-lay this section with proper adhesive and leaving boards in room for the week, is it likely to do the same again ?
The floor is glued down and there is no expansion that i can see to any other wall but this was the only area that had cupped. Do i need to go around the whole floor and cut an expansion gap?
I didn’t think that it was correct to lay this floor with no DPM or insulation etc. Was this floor laid correctly in the first place?
Am i totally to blame for it cupping the second time, or would this of happened down the line, just a little slower ?
I really want to sort this out for the customer and to give her the best information and advice i can and i’d like to thank you guys in advance for any help you can give me.
