Damp under parquet even after some work

[Garyivy]

Afternoon guys.
Been renovating a property for the best part of 12 months and I assumed, incorrectly, that I had solved our damp issue.

This image was of the property before any work was undertaken

Since then we’ve had new wooden doors, repointed the mortar outside and repaired/replaced the blocks above, which now gives us this



I’ve since dug out under the doors as the patio was just collecting water and I assumed causing the damp floor issue



Internally we’ve got this



The blocks that I’ve lifted to the right had damp (arguably water) underneath them but I’m at a loss as to what’s causing it.

When repointed have I locked water in?
Is the floor below the parquet letting water through?
Is it just rising damp from outside (a very old dpc I think) which is then penetrating and collecting internally?

Any thoughts MASSIVELY appreciated

Thank you

 

[RBailey]

What is outside the door now? is it still the pooling water?

What is the fall on the remains of the patio like? is it directing water towards the doors our out of the area? are there any gutters that drain onto the patio?

A small French drain (gravel trench) with a fall away from the area may help move the water and let it dry.

Cheers,
Richard B.

 

[Garyivy]

Outside the door currently is this, so 2 and a bit bricks below the door.



Only with really heavy rain does it look like the initial photo and even that drains.
The fall on the rest of the patio is still towards the house


And that drain pipe in the left previously overflowed as it was above surface and the bathroom plus roof water went through it but is now straight into the drain.

Could it be as simple as gravel up close, aco drain in and patio fall away from the property? Garden hasn’t been touched yet so I don’t mind some excavation there at all.

I was contemplating putting injectable dpc in too?

 

[Cubist]

It looks to me like many of the parquet blocks in the floor have absorbed quite a lot of water through their end grains, hence the dark/blackened patches. Given how far that discolouration of the blocks seems to extend into the room I would suspect the source of the water is unlikely to be from outside what I think is a new window/door frame. Are there any sources of water - ch and water supply pipes - in the room? Are any of these embedded in the walls? Was the room left exposed to weather while the new frame was installed? The pattern of discoloured blocks in the room may suggest the origin/location of an internal leak.

 

[Garyivy]

Thanks for replying guys.

The original picture with the single door was prior to any work being done. Then the damaged pieces were replaced, with slightly different coloured blocks as below.
This wider picture may help and shows the only water source, internally, that is close. This did have a leak a couple of months back as some of the blocks below with water marks are much less visible.
Aside from that though there aren’t any pipes close to the back door.

The new doors were fitted towards the end of the summer, exposed yes but relatively dry. Then I did some remedial work and repointing underneath as it was like this




Both photos prior to repointing

Thanks again!

 

[Garyivy]

There was definitely water coming in under the door, prior to repointing etc and the floor blocks were laid within a few days of pointing and clearing the outside space.
Could it be I’ve almost locked some moisture in and not let the floor dry before relaying the parquet. Then a small radiator leak has added to it?

The blocks look much wetter in this picture from November vs the one after today






Thanks again!

 

[Cubist]

As you probably know parquet is typically laid with a strong contact adhesive of one sort or another that as well as sticking the blocks to the floor provides a barrier to prevent damp rising through the floor and damaging the wood. However, parquet is vulnerable to water damage if the upper surface and all joints are not protected with a suitable sealant. My guess at present is that all the damage you are seeing results from both rain-water incursion via the the underside of the door-frame and the c/h leak you mention but would suggest that the bulk of the damage is due to the latter.

I suppose you have already checked to make sure there is no evidence of water coming in under the frame during heavy rain and when strong winds may drive rain against the wall and door frame? If so, and you're confident that the c/h plumbing is ok then you will need to wait to let the parquet fully dry out - keep the room warm and well ventilated - before you can begin repairs to the surface.

 

[Garyivy]

I hope it’s as easy as that Cubist thank you!

The CH leak was mild at the extreme if I’m honest.

Under the door has a roll of dpc butted up, back from the drip tray and mortared underneath.



I’ll likely use some dry zone DPC to the brick add some French drains and loft the first row of wood blocks and see if they naturally dry with some heat and a de-humidifier etc.

Unsurprisingly after a very brief description a damp specialist said it was rising sub floor damp, which it may well be, but that fix sounds much harder than the others.

 

[Cubist]

Just an afterthought - an easy test for penetrating rain perhaps driven by wind uses a pressure washer played over the frame edges and door/window closures from a couple of feet away. Any weaknesses will soon reveal themselves and I would suggest you pay particular attention to the bottom edge of the doors.

 

[Garyivy]

Good idea that thank you.

I plan to lower the patio while putting in some French drains and checking existing drains.
DPC externally, although solid walls is this a good idea?

Take a few blocks up internally working back from the doors until a dry area appears. De-humidifier to dry out and test with your suggestion.

Worst case is to lift a few more blocks, dry out, new screed and DPM and relay blocks.

 

[Cubist]

Sounds like a viable plan. Good hunting.

 

[Garyivy]

Thank you for your pointers, appreciate it

 

[88v8]

Looks as if the sub-floor would be level with the external ground surface.
Where is the dpc... height above ground?

Parquet used to be bedded in hot bitumen, depending on age of house.

 

[Garyivy]

So, after some investigative work it looks like the water is coming in around the DPM that you can see below the sill.

The water is coming in both below the DPM and above it, below the french doors.

The fix to this in my mind is to cut back the DPM so its hardly visible and use exterior silicone around it to prevent any future ingress.

Any pros or cons to this?

 

[Cubist]

It's rather puzzling given the height of the frame cill that you're getting water ingress there - the rain would have to bounce quite a way, and heavily, to produce a noticeable incursion. Are the drip rebates clear and unobstructed? Is a a pressure washer regularly used near the frame (other than for the test I suggested)?

As to using silicone sealant. It will work provided that theres a small gap between the bottom edge of the cill and the wall to form a rebate key. This will help the silicone to form a strong bond between it and the DPC material. Given though that you think water is coming in 'under' the DPC as well, you may need to seal that joint too.

Sadly, I suspect that the window/door frame is not sitting down properly on the DPC material and the lack of compressive forces is the root of the problem.

 

[Garyivy]

Thanks Cubist.

I'm thinking that the run of water from the sill is somehow collecting and running above the membrane and the drip rebate (which i guess is the line you can see under the sill) isn't working properly?

This is the picture yesterday and you can see where it has flowed.




The installers of the frame were adamant a DPM wasn't needed (I didn't agree), so when I was scraping back and repointing the mortar I retrospectively added one and so it doesn't surprise me if there isn't pressure on the DPM from the frame above.

 

[Garyivy]

Given though that you think water is coming in 'under' the DPC as well, you may need to seal that joint too.

This may not be the case, it may be coming in over the top but once it is in the water then finds its level which is underneath the DMP, you can see the line where the DPM ends.

 

[Cubist]

so when I was scraping back and repointing the mortar I retrospectively added one and so it doesn't surprise me if there isn't pressure on the DPM from the frame above.

Do I understand correctly that you installed the DPC 'after' the frame was installed?

 

[Garyivy]

yes .... I feel like you're going to tell me i made a big mistake now.

The door installer said it wasn't needed but being wood I disagreed so while scraping out perished mortar I could get it under the frame as the frame was held in at the sides.

 

[Cubist]

I'm really surprised by your window fitter, theres no excuse for installing it in a non-weatherproof fashion. They should have ensured it was completely sealed against water penetration on all sides before they left the site. As it is, they have created a situation in which rot in the frame, particularly in the foot, is almost certain. You were right to want a DPC of some sort but they should have required that it was installed before the frame was fitted or done it themselves. You may be in a position to register a complaint/claim. In terms of remedial action; get the foot of the frame covered to prevent further ingress of water and get try to get the bottom section as dry as possible. Assuming the fitters will not take action to remedy the problem I would advise that you clear out the gap above the DPC and use an expanding foam injected between the frame and the DPC - you'll need to dam the inner face to prevent the foam escaping indoors - the foam may then produce sufficient downward pressure on the DPC for it to work effectively, but I would be tempted to get rid of it. When the foam is set/dry carve out a bedding slot outdoors that can then be filled with a silicone sealant. Given the calibre of the window fitters I would also be tempted to carefully examine all the seams around the frame to make sure they are sound and weathertight - theres a chance that the water you're seeing may be coming in at the top or sides of the frame.