Securely fixing floor joist to block wall.

9 Apr 2021
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United Kingdom
Hey everyone, so a floor joist in my kitchen has rotted across most of it's length due to some prolonged water damage (now sorted). I'm going to replace the joist completely it was attached with a few big nails into masonary and had dropped, doesn't seem secure for a floor that sees heavy use in that spot.

I should mention the joist removed was 2.8m, flush to the wall, and with no dwarf wall underneath.

Looking for the most secure way to attach it to the masonary so there's no chance of it budging ever again, any recommendations?
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From your description it sounds like the joist is parallel to the wall and runs along it.
If that's the case, wall anchors should do the trick and some noggings would prevent any movement and make the floor firmer.
Instead, if the joist is at 90⁰ to the wall, use a masonry joist hanger and follow the manufacturer's instructions.
Simpson strongtie have technical drawings for all their products with detailed installation instructions.
Concrete screws with a length 2-3 times that of the joist thickness would also suffice, if the bricks will take them without dropping to bits. 300mm centres will likely be fine; it's quite a quick job, once the two ends are in, to just go along the ledger zapping a 7mm hole with an masonry SDS, right through the wood too, and winding a concrete screw in
It should bear directly (or via a hanger) on masonry at each end, not be screwed to a wall at the side.
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OP, given your future concerns, why not post a couple of pics showing the exposed floor joists, esp the seating of the joists at either end?

As above post #4, dont pin the joist to the parallel wall - its a joist not a ledger.

OP, what was the cause of the water damage?

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