Floorboards, Walls, and D-D-D-D-amp

[chapel]

Hey all,

So 17th Century Timber Framed house - brick infills.

One of these infills on the ground floor (exterior) wall has just been completely rebuilt (lime mortar and lime plaster inside).

We've just noticed there's a damp patch on the floorboards extending along the junction of them and the rebuilt infill. The wall actually sits on top of these floorboards (by at least a little bit)

I really just want to check the construction method here - how are floorboards meant to sit/relate to the sill beam? Would they have traditionally just sat an inch or so onto the cill, and then the wall built up on the rest of the cill? Would the floorboards have been in contact with the wall itself?

I would check around the other exterior walls but the all have skirting boards which i'd prefer not to mess around with as they'll never go back.

thanks all

Paul

 

[robgil]

its hard to say Paul whats causing the damp , are there any leaking rainwater pipes out side or gutterings?
with damp ive always thought that getting to the source is the only way to properly resolve it.
i would also have thought the floor boards would have butted up the the plinth underneath the sill beam , i really cant see anyone building a brick infill ontop of the floor boards. are the floor boards original or an after thought?

 

[chapel]

There's no leaking rainwater pipes and ground level is a good 8in below floor.
The sill beam (what remains of it) sits on rag stone/lime mortar foundation about 6in above ground level. Where the beam is bad its been covered with lime mortar.

I think that moisture from either the outside, and/or the wall/plaster as it's drying, is making the edge of the floorboards damp. The wall is breathing away but the wood its in contact with is not as happy.

The floorboards are original and the infill panel mentioned was rebuilt this summer. I think about an inch of the wall sits on top of the floorboards, and the remainder on the sill

I may be entirely wrong...

 

[robgil]

is the wall rendered on the outside? is it cracked? any chance of a pic? how much moisture are we talking about here and how long ago was the infil rebuilt? surely the lime plaster should be dry by now if it was rebuilt earlier in the summer.

 

[chapel]

Hi,
The wall isn't rendered outside - no cracks either. Infill was done in May. Internal face has had 3 coats of lime plaster, with the last going on a week ago. It may well turn to be left over/residue from previous situation where the infill was cement rendered inside and we were getting damp - maybe its taking months to dry. It may be from the final coat of plaster- from the sponging off. We only notice it a week ago around when the final coat went on - but that also correlates with one hell of a lot of rain we've been having.

Any thoughts on the floorboard situation? Guessing they should just butt up and not go under..

thanks ,Paul

 

[Penners]

The way that your floorboards are arranged will depend very much on how their supporting joists are arranged. I suspect this will vary enormously from house to house. I can only say that in a period property, were I installing floorboards, I think would try to have them stop a few millimetres short of contact with the external walls (joist locations permitting). The skirting board would then cover that small gap. This could help to protect the floorboards from any moisture ingress through the walls.

Your comment about "what remains of" the sole plate may be a factor in your problem. If there's some water ingress around a deteriorated sole plate, this could find its way through to the floorboards - assuming they're in contact with the outside wall.

On the other hand, it's possible that the signs of damp you're seeing in the floorboards adjacent to the rebuilt infill come simply from the wet lime mortar used when the job was done. How long ago was the work carried out? Do the floorboards still seem actually damp, or are they just stained?

 

[chapel]

Thanks Penners - the sole plate is no longer visible on the exterior of the wall - the worst of it was removed and what remains was coated in lime mortar. Maybe the damp comes from the residual mositure in the remains of the sole plate, but i dont see that it can be coming from outside.

It's not staining on the boards, it's actually damp. our attention was drawn to it because we noticed the carpet was wet along the length of the wall.

I've spoken to builder who did the infill and he has said that the wall does in part sit on top of the floorboards as there wasnt enough of the sole plate left to build on.

He's coming over later in the week so we'll see what's what and where we go

thanks all

 

[robgil]

why didnt he just replace the sill plate?

 

[chapel]

Mixture of cost and time.
We had a well regarded woody expert come along when we were dealing with the outside and he suggested we could get away with cutting out the worst and making good using slate/lime/rag. This was before we decided to rebuild the infill panel though. Time wise - we had a 5 month old baby in the house and wanted to get it done in a day.
The fix may well be to cut a channel at the bottom of the wall on the inside (it should support itself), insert a plate and cut back floorboards a couple of inches providing joist is suitable.
Oh the joy!