Floor joists and hangers

22 Nov 2009
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United Kingdom
I'm adding some deeper joists
to form a floor in the front part of my loft. A full loft conversion is planned for the future but this will be at the back of the house. The front will be for eaves storage - but we have a lot of stuff so realistically the loading will be quite high. I'll use 175 or 200 x 50 at approx 400mm to span 3.4m. I want to drop the joists to finish a bit (60mm)below the existing 70mm ceiling joists as headroom is tight in the loft. The joists sit directly on the brick spine wall internally so I'll be able to cut slots in the top of this to drop the new joists in. On the eaves end the joists sit on a 75mm deep timber wall plate. How can I fix the joists? I could notch 60mm out of the joist ends to sit them on the wall plate and support the bottom section with timber mini joist hangers? I don't think I could get far enough into the eaves to either build up the wall plate and/or nail a larger hanger securely. It won't be inspected but obviously I want something structurally sound.


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I did similar and put an RSJ accross about 1.2mtrs into the room then hung the new joist off that and onto the centre wall as you say. On the centre wall I removed 2 courses of brick and bedded on a 4x2 wall plate for the joists to sit on.

If your having a loft done in the future you might as well hang on.
Thanks. It takes me a while but after a bit more thought, and bearing in mind the need for insulation (I was planning to fill the joists with rockwool and put a layer of celotex on top between the joists and flooring) I've decided I'll just sit the new joists at the same height as the existing and fit 60mm celotex under the joists with PB under that - bedroom ceiling below is coming down anyway. I also need the new ceiling to be lower to avoid boxing in the steel for the chimney breasts as this sits a bit lower:
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Now are you doing both side of the spine wall, or just one. If both, then take off the top layer of bricks. If just one, then set the new joist in the centre of the old one, and cut a slot where needed with a diamond blade.

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