No DPM under door. Rotten floorboards

[VioletG]

My partner pulled up the laminate floor in our Edwardian house and discovered the floorboard next to the doors was rotten.

It looks like there is no DPM. I'm not sure if you can tell from these photos.

What are the options to resolve this? No point in replacing the boards until this issue is fixed.



With the board removed



Thanks

 

[blup]

Cut back the joist where it touches the wall, and treat. Replace floorboard. Ideally install upvc doors

 

[ree]

The concrete slab is allowing moisture to penetrate below your door.
You dont have an effective threshold - you have a built-up box arrangement thats showing signs of rot.
If you remove the skirting board you could check inside the box for rot? The whole box arrangement might need replacing?
The previous, probably rot damaged, joists were replaced with the new'ish joists that we can see - the tails of the joists need cutting back - treating with anti-fungal chemical - and capped in DPC material.

For the time being, remove all proud nails & loosely replace the floorboard.
How high is your suspended floor off the sub-area soil?
Do you have airbricks every 1500 - 1600mm along the elevation?
Any smells of mushrooms?

 

[VioletG]

The concrete slab is allowing moisture to penetrate below your door.
You dont have an effective threshold - you have a built-up box arrangement thats showing signs of rot.
If you remove the skirting board you could check inside the box for rot? The whole box arrangement might need replacing?
The previous, probably rot damaged, joists were replaced with the new'ish joists that we can see - the tails of the joists need cutting back - treating with anti-fungal chemical - and capped in DPC material.

For the time being, remove all proud nails & loosely replace the floorboard.
How high is your suspended floor off the sub-area soil?
Do you have airbricks every 1500 - 1600mm along the elevation?
Any smells of mushrooms?

Thank you for the reply.

What is the box? I'm not sure what that refers to.

One joist is actually rotten at the end, directly below that door. We know all these joists were done in 1988 because the floor was laid with the laminate and not removed until my partner pulled it up.

That area of the house sits above a coal storage, which is probably about 4ft high. Although that area is part of the original house, we call it a lean to. You can see it's the section beyond the arch.



There are air bricks outside



But perhaps an issue here, is that back in 1988 they added a ceiling to the coal storage and then above that put pipes and loads of insulation. Which I assume means the airbrick is doing very little.