Beam and block floors

[DanTheMan]

I know this is a necro thread but I thought I'd chime in anyway.

We've got a 1950s semi with a void of 700mm under the ground floor. Our joists and floor felt quite bouncy but the joists were structurally fine.

I considered all sorts of options but the costs Vs the reward seemed not worth it.

In the end we just went for glue down lvt, with 9mm ply over the floorboards, a layer of screed and then lvt. It was by far the cheapest and most obvious option and it's made a world of difference in both insulation, sound and bounciness.

I'm sure block and beam or solid concrete would be even more solid but it's one of those things where, once it's done, it becomes such a none issue that I'd be annoyed if I'd paid thousands more and a lot more upheaval for not much gain.

 

[Vestas]

You can stiffen up bouncy floors by either glueing/screwing ply along each side of the joist or wrap metal strapping around it ( https://www.finehomebuilding.com/1994/07/01/floor-joist-reinforcement ). The ply method is easier if its an upstairs floor & I used that myself on a previous property where the joist span complied with building regs but was optimistic.

Also noggin the joists properly to distribute load.

 

[danlightbulb]

Old thread indeed.

I have bouncy floor in back living room. I believe underfloor sleeper wall has collapsed in one spot. I'll be rebuilding it, new joists in, new noggins in, insulate, reboard.

Retrofitting beam and block is not worth it. Also filling in with concrete probably not worth it, my floor void for example is over 1m deep.

 

[Chojin]

I didn't go ahead with the beam and block floors, my project is still pending, and has evolved over time.

I think beam and block would have worked, but since my project has a rear extension I am leaning towards an insulated concrete slab and have the ground floor on a single level.

The lower cost options mentioned in this thread are definitely the sensible approach, and I'll be looking at something like that on the upper floors e.g. metal-web joist, plywood and screed board combination.

 

[Vestas]

One thing to bear in mind is that there's a quite remarkable number of joiners/builders out there who are under the impression that if you use T&G flooring then noggins aren't required. This is of course complete ****** unless you're using engineered joists so be careful about "advice" from chippys, especially the younger ones.

 

[MassiveJim]

I didn't go ahead with the beam and block floors, my project is still pending, and has evolved over time.

I think beam and block would have worked, but since my project has a rear extension I am leaning towards an insulated concrete slab and have the ground floor on a single level.

The lower cost options mentioned in this thread are definitely the sensible approach, and I'll be looking at something like that on the upper floors e.g. metal-web joist, plywood and screed board combination.

you still haven't sorted this, it was 7 years ago