Air brick on ground level

[Jordan87]

Evening all, my first post on this forum.

Just after some advice, I've recently bought a property and on the first day a joist broke, so I've took laminate flooring and floor boards off and the joist was wet and rotten to the core and the 2nd one along was the same although hasn't give way (yet). My question is directly behind the joist that broke is the outside wall with an air brick at ground level. Could this be causing the damp underneath my floorboards hence rotting the joices? See pic

Many thanks.

 

[Doggit]

It's not the air brick that the problem, it's the ground outside that's been raised above the DPC, that's then let water through the brickwork, and soaked the end of the joists. You'll need to dig out a 4"x maybe 8" deep trench outside the wall to stop the water getting in- use a diamond blade on a 9" angle grinder When the walls have dried out a bit, then you can bitumen the wall and either fill the trench with 1" stones (pea shingle gets clogged up with dirt, and stops being effective) or use something like this http://www.wickes.co.uk/Clark-Drain-Polypropylene-Channel+Grate-1000mm/p/158852, but only as long as it goes below the DPC.

To fix the joists, you'll cut about a foot off of the end of them, then fix a 1.5M joist alongside, using 3 x M10 coach bolts, and a square washer on the nut end. You need to put a piece of plastic DPM under and around the end of the new joists, and they should preferably be treated rather than plain - you'll very likely have to cut a new slot in the brickwork for the new joist position. Keep an eye on the joist to make sure they stay level whilst you're doing the job, and then replace the floorboards, and you're done. Make sure you check every joist along the wall plate - if you can stick a screwdriver into the wood, then ideally, it should be repalaced to make sure the wet rot doesn't change to dry rot.

 

[vinn]

Can you get under the suspended floors and examine all the joist seatings in all external or party walls?
Why not walk around the house and examine the height of the ground level against the DPC on the outside wall.
Usually, the air brick is sitting on the DPC.
Air bricks should be free of rubbish and spider webs.
Why not remove the laminate and floor boards along that wall back about 600mm and post photos of whats there?
Have you examined the inside wall surfaces at skirting level for signs of damp. If you intend to re-decorate then strip wallpaper off.

 

[Jordan87]

Thank you for the replys. Sorted the joists using your advice and done trench. Fingers crossed they don't rot again.