Unlevel week floor

[GARRYD]

hi all

My problem is that i bought a house built back in the 1890's. it is a two up two down terrace. the first floor's all sag very bad towards the middle from the sides. on closer inspection i found out that the joist are only 4 inch by 2 which i dont think are strong enough as it sounds like someone is going to come through the floor when they are up stairs and you down stairs. the wood in both floor boards and joists has being damaged in places by some sort of termite as in places it is covered in small bore holes. please advise in what the best way to sort problem with the least expensive

[kybert]

If the floor is sagging that much, then id replace the floor. This will involve new joists, and hence new ceiling downstairs.

If the floor boards are rotten also, then they will need replacing. The bore holes sounds like wood worm. You can treat that yourself with a pump spray gun (go to garden section), and a tin of wood work killer from b and q. Treat all exposed services as you go.

Now to replace the joists, you will have to move out for a week. Remove the ceiling down stairs, and the boards upstairs and any rotten wood take to the tip at once or the worms could still be in there and fly out to another part of the house.

Remove ONE joist at a time, to do this, cut a 2ft piece out of the middle of the joists, and pull the remaining wood out of the wall. This is easier than beating the joists out with a hammer!

Replace the joist with a new one from the buildcenter. Get treated wood, tell them its for a joist and they will tell you what treatment it needs.

Repeat one at a time.

Spray the new wood with the wood worm killer also.

Not sure what size the joists need to be, but the ones in my house are 2x8 inches (1930s house).

This is a major and messy job, easy to do, but messy and needs plasterer to skim the ceiling after you have plasterboarded it. Use pink plasterboard (fire check).

good luck!