Replacing floor joists Kitchens, doors, rails, stud, tables, chairs, stair cases, garden furniture etc... Find answers and ask questions here!

[Cat80]

Hiya, I'm new to this site and is desperate need of some help. Our floor joists under the bay window have just given away and the floor has collapsed at that end of the room. We live in that room so are squashed into just a 3rd of the room. We need to replace the joists asap. I've never done anything like this before so any help is much appreciated.

The joists have rotted away. They go across the room and I have no idea what to do. How do I fix them? What do I fix them to? What wood do I need? I'm a complete novice when it comes to this and don't have much money at all. Also I have no insurance so can't claim on that. Any help is much appreciated, thanks :D

[Cat80]

Just a thought. Would I be able to just fill the floor with cement and cover it with wood? A cheaper option and something I could do myself.

It's just we are worried about the house being sturdy and I have no spare money and no insurance so am at a loss as to what to do.

[Greg40]

Hi.
A common practice in this situation is to rip up the wooden floor, then dig down to a suitable level, then fill with the appropriate depth of hardcore ( we use lime stone 40mm to dust around here as it is local and cheap), blind with sand. then in with visqueen sheet , then concrete.
Hope this gives some idea
Greg

[thedoctor]

See our project on replacing a timber floor to get the idea on how to do it with timber. Also see our project on ground floor slabs to learn about concrete slab construction. The problem with replacing with concrete is that although, as the post above says, a damp proof membrane (visqueen) is required, it need to be cut into the walls to stop any damp coming up (capillary action) between wall and DPM. Because you have a timber floor in this section you are likely to have an air brick in the outside wall to ventilate it. Blocking this ventilation may also block the ventilation to other parts of the floor which may lead to rot in the other timbers. If the floor is rotten as you say, then this ventilation may alreadyt be blocked so look for that and try to remedy. The rot also suggests thyat its already pretty damp under there so tucking in the membrane would be even more important.