My rotten floor/s

[JohnD]

I have the black plastic pipe, branded Alkathene. mine has the maker's id printed or stamped along the side. Useful to check as it is likely to be an imperial (not metric) size, which you need to know if you ever have to get a fitting such as a replacement stopcock.

If you take the floor up, you can clean out all rubbish and clear the airbricks, and lay mineral wool insulation between the joists - and especially round the edges of the room where draughts blow up under the skirting.

You will have to replace those soft joists which are presumably rot or worm damaged. I like to apply wood preserver to joists when I have the floor up, or if replacing damaged timber.

 

[JP_]

Will the plasterboard be sitting on the joists too, or should I be able to remove them without having to take too much down?

 

[Ian H]

The plasterboard will be stuck to the wall and finish above the floorboards.

 

[JP_]

Sounds like it could be easier than I thought then ... just a case of removing wood, chucking out anything rotten, treating everything left, cleaning up, and putting in new ....

What could go wrong? I am crap at DIY. But, willing to have a go.... Might need a bigger saw.

 

[John D v2.0]

I'm doing exactly that task DIY, this week end is on the hall floor, so it's definitely doable. I would recommend against concrete as the water is at least evaporating at the moment, if you concrete it may build up in the walls and cause a different problem. Dpc only work when they are fully continuous.

Piglet John is spot on with cleaning all the rubble out and adding plenty of wood preserver, but if any wood is actually rotted rather than just wet I'd definitely replace. In my case with a new sleeper wall next to the old one, then blowing the old one way. This maintains the levels.
The new wall plate will end up slightly too low so I use folding wedges to provide support to the existing joists at the existing height.

Good luck!

 

[JP_]

Luck - I need some!

Seriously though - did you see my question about plastic joists? In a floor with a history of getting wet / damp, I cannot help thinking that they must be a good option? It will never rot and won't allow water to pass through either, and won't act as a sponge to then increase humidity.....

New sleeper wall - not sure my skills are there yet!

 

[John D v2.0]

Plastic joists sounds a bit fancy.
When I say new sleeper wall, our old one are just a row of bricks on the hardcore.
The new replacement is just scrape off the hardcore to something more solid or just the mud, dump in some mortar with a brick on top, then mortar and a doc on that.
In the first room I was like you so I just used a bit of spare wood to lever up the joists slightly and inserted the doc. The joists I hope are drying out slowly themselves.
But as I got more confidence and I found wetter and more rotten wood, I started to replace the worst ones.
The trick with DIY is to start with something you don't quite feel confident with, and keep doing things you don't quite feel confident, and before you know it you're doing things you'd never dream of doing a year earlier!

 

[JP_]

What's a doc? Google is not helping me on this one!

 

[John D v2.0]

Sorry dpc. My new phone has a habit of auto correcting things after I typed them in manually
At least the old one would only auto correct while you were typing.

 

[JP_]

lol, that makes sense!
Emailed my neighbour who is developing a couple of local houses - says "There will be a tar damp proof course on the brickwork but if any of the air vents around the property have been blocked it tends to lock the damp in and then start rotting the timbers!!!"

So, time to get that bottle cleaner and torch out again!

 

[John D v2.0]

Might be beyond your current confidence level, but I bashed out for 4 new air bricks in the lounge.
We had 2 existing but one was painted over mostly and one was just mucked up.
I made the side one double height and added 3 more at the front.
More ventilation only works up to a point, the main thing is to avoid dead zones not to have a gale blowing through.

 

[JP_]

Well, lack of air bricks did come up on the building survey. And, I just looked - the left side of the house only has 3 air bricks, and ground levels have been raised for some reason.
Added photos to https://photos.app.goo.gl/SzWlcaKi61TSRvDY2 - the first 3 are left side, the other 4 are right side.

Time to get the SDS drill out. ....

 

[John D v2.0]

Time to get the SDS drill out. ..

What's the worst that could happen?

 

[JP_]

Lol. At least its only a bungalow - less wall to pick up.

 

[JP_]

Screwdriver test ....