Thanks, like these?
The prior pics are under the left side window (seals etc look good to me, damp is all round anyway)
Solid concrete floor 1.5" below DPC - damp
- Thread starter dormermike
- Start date
Thanks, like these?
The prior pics are under the left side window (seals etc look good to me, damp is all round anyway)
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Hi woody, just wondering if the pics revealed anything?
Thanks
Thanks
This DPC (bitumen) is it sandwiched between two bricks ie horizontal and you can just see the edge or is it painted vertical on the bricks?
Hello - it is sandwiched horizontally. There is nothing on the face of the bricks below that line of bitumen. Below the line of bitumen, it is wet in places, which is then causing a damp patch on the concrete floor. I've "fixed" it in the other front froom (second bay) by painting bitumen based roofing felt adhesive into the face of the brick and the concrete floor, effectively lapping up the bitument under the parquet blocks into the wall DPC. That worked for the most part, those in places you could see it was a little "blown" I guess caused by moisture coming through.
I am tempted to try squeeze silicon sealer down the 2-3mm gap between the floor and the wall, to see what happens..
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It looks OK from the outside ... if that render is in good condition
I just wonder if the painted red bricks are preventing some natural evaporation of moisture, and instead containing it within the wall. Perhaps not a cause in itself, but just another factor to cause a wall to be wetter than it should be
If your previous methods have worked, then just carry on
Silicone wont help, and might react with any bitumen product. Just seal it all with bitumen or a different surface DPM product
I just wonder if the painted red bricks are preventing some natural evaporation of moisture, and instead containing it within the wall. Perhaps not a cause in itself, but just another factor to cause a wall to be wetter than it should be
If your previous methods have worked, then just carry on
Silicone wont help, and might react with any bitumen product. Just seal it all with bitumen or a different surface DPM product
Thanks again
Im not sure if its related but some patches of the brickwork on those bays seem to take a lot longer than the rest to dry out after heavy rain, almost looks like water is coming out of tge wall through the pointing/mortar. Maybe the paint has something to do with that as you suggest.
Render is in ok condition, i had the pointing redone 2 years ago too as it was full of gaps, didnt make any difference at all. I guess because its a cavity.
Cheers
Im not sure if its related but some patches of the brickwork on those bays seem to take a lot longer than the rest to dry out after heavy rain, almost looks like water is coming out of tge wall through the pointing/mortar. Maybe the paint has something to do with that as you suggest.
Render is in ok condition, i had the pointing redone 2 years ago too as it was full of gaps, didnt make any difference at all. I guess because its a cavity.
Cheers
Just a thought, two houses 1930s, in my street had damp problems around the bay, both had broken U bends at the bottom of the down pipe.
Another on a 60s house was full of roots from a hedge, 4M long! He was complaining of his gutter overflowing.
Another on a 60s house was full of roots from a hedge, 4M long! He was complaining of his gutter overflowing.
Pred, thanks - was that shown up on a CCTV survey? I am thinking of getting one of those done as a sewer does indeed run via the front of the house underneath that path. No other signs, but for £100 odd it may be worth it for piece of mind.
haha! I dug a hole to the side of the house approx 75cm deep (well below floor level) and whilst the sides (clay) are often very wet it hasn't filled with water, ever. At the front, where I think the dig should take place, I dont really want to disturb the blocks if I can help it.
Do you have any pics of your graft, be interested to see what it looked like?
Saying that have been considering removing a brick or two from the front bay to see whats what inside the cavity. I put a camera in but it didn't show much and all seemed to be dry, other than the mortar. I know rising damp is not supposed to exist, but in this case I think the humidiy differential between the cavity (vented) and the interior room (60% in center at present) is drawing moisture up through the black mortar. Or i'm talking complete horlix
haha! I dug a hole to the side of the house approx 75cm deep (well below floor level) and whilst the sides (clay) are often very wet it hasn't filled with water, ever. At the front, where I think the dig should take place, I dont really want to disturb the blocks if I can help it.
Do you have any pics of your graft, be interested to see what it looked like?
Saying that have been considering removing a brick or two from the front bay to see whats what inside the cavity. I put a camera in but it didn't show much and all seemed to be dry, other than the mortar. I know rising damp is not supposed to exist, but in this case I think the humidiy differential between the cavity (vented) and the interior room (60% in center at present) is drawing moisture up through the black mortar. Or i'm talking complete horlix
Water moves in mysterious ways!
Still havent got round to doing anything with this other than watching it, but currently pondering that in the midst of very long hot dry spell the damp patch is still coming and going through the day.
I poured water down the outside of the bay soaking the cill and brickwork (the vent seemed to get soaked due the drop of the cill but am not sure if any actually went in) and the damp patch may have got marginally worse.
When i get up the courage I think i'll take a brick or two out of the cavity wall near the worst part of the damp and take a look. That said, it wouldn't explain the damp at the base of the other (internal) wall which obviously doesn't have a cavity due to it being, well, internal.
Continuing to ponder..
I poured water down the outside of the bay soaking the cill and brickwork (the vent seemed to get soaked due the drop of the cill but am not sure if any actually went in) and the damp patch may have got marginally worse.
When i get up the courage I think i'll take a brick or two out of the cavity wall near the worst part of the damp and take a look. That said, it wouldn't explain the damp at the base of the other (internal) wall which obviously doesn't have a cavity due to it being, well, internal.
Continuing to ponder..
Going to get a CCTV drain survey done, booking them in for september. A drain runs along the outside of this room and i've just been out weeding in the garden which is next to this room and noticed the soil is damp near the surface, and there was even damp/mold at the bottom of the garden wall (half of first course of brick) which is highly suspicious seeing as we've been in a heatwave and not had rain for ages.
Digging elsewhere in the garden turns up dust (very dry to quite a depth as we've had no rain for ages), so the water in that particular area must be coming from somewhere. The mains water supply also runs along this stretch.
Pointless investigating internal damp issues if the outside is damp?
EDIT: I lifted the inspection cover which is by the side of the damp room and near the damp soil and it was free flowing with no build up of anything, however where the toilet empties into the chamber the "jet" of water seems to have eroded the concrete near the clay gulley. Similar to this picture (which is not mine as I didnt take a photo but does demonstrate point) though my crack is slightly bigger.
Once the flush water emptied into the chamber most of it quickly disappeared down the gulley but some of it could be seen sitting inside the crack. Thats a meter below where any of the damp is appearing - can't be helping though? or is that normal?
Thanks
Digging elsewhere in the garden turns up dust (very dry to quite a depth as we've had no rain for ages), so the water in that particular area must be coming from somewhere. The mains water supply also runs along this stretch.
Pointless investigating internal damp issues if the outside is damp?
EDIT: I lifted the inspection cover which is by the side of the damp room and near the damp soil and it was free flowing with no build up of anything, however where the toilet empties into the chamber the "jet" of water seems to have eroded the concrete near the clay gulley. Similar to this picture (which is not mine as I didnt take a photo but does demonstrate point) though my crack is slightly bigger.
Once the flush water emptied into the chamber most of it quickly disappeared down the gulley but some of it could be seen sitting inside the crack. Thats a meter below where any of the damp is appearing - can't be helping though? or is that normal?
Thanks
Sorry if i'm boring anyone with this but i managed to get an old laptop cam onto a stick along with the flash LED from an old blackberry, in order to get some hi-res shots of the inside of the cavity of the front bay, right into a section of wall either side of this damp spot (which incidentally, is much worse than shown in this pic, at present):
It looks like the cavity is indeed blocked up in places after all, something that I couldn't figure out on my cheapo clas olsen flexible camera as its too low res.
This shot is looking to the left, and the wall on the left side of frame is the inner leaf. The black bitumen DPC is visible, so we are just below that height:
Another left hand side shot, looking further into cavity (does look dry in fairness?)
Next shot is looking toward RHS but also upwards slightly (the DPC is vertical thick black), and clearly shows a damp spot on the rear of the inner leaf (right of frame) which corresponds to a damp spot on the inside wall.
Finally, looking almost straight up into the cavity, you can see the external wall DPC on the right hand side of frame and also an old rusted wall tie. Above it is a piece of timber which bridges the cavity. Could that have been put in place by the brickie in order to keep the gap consistent? There is no damp on the internal wall above DPC level so I dont think it is causing any problems:
Any thoughts on the above would be appreciated.. havent had drain survey out yet, is booked for next month.
It looks like the cavity is indeed blocked up in places after all, something that I couldn't figure out on my cheapo clas olsen flexible camera as its too low res.
This shot is looking to the left, and the wall on the left side of frame is the inner leaf. The black bitumen DPC is visible, so we are just below that height:
Another left hand side shot, looking further into cavity (does look dry in fairness?)
Next shot is looking toward RHS but also upwards slightly (the DPC is vertical thick black), and clearly shows a damp spot on the rear of the inner leaf (right of frame) which corresponds to a damp spot on the inside wall.
Finally, looking almost straight up into the cavity, you can see the external wall DPC on the right hand side of frame and also an old rusted wall tie. Above it is a piece of timber which bridges the cavity. Could that have been put in place by the brickie in order to keep the gap consistent? There is no damp on the internal wall above DPC level so I dont think it is causing any problems:
Any thoughts on the above would be appreciated.. havent had drain survey out yet, is booked for next month.
Me again - the cavity is pretty much full in the places i've looked, and makes it approximately equal to external ground level height and internal floor height, so the damp could very well be penetrating via the bridged cavity to the internal floor level.
What I don't think that explains, is the damp at the base of internal single skin interior walls, or could it?
What I don't think that explains, is the damp at the base of internal single skin interior walls, or could it?
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