Strengthen my 1st floor for my home gym

[mikeinthemidlands]

Hello

I’m planning on using my spare bedroom as a home gym so I’ve started work on removing the 22mm chipboard flooring to replace it with 25mm plywood.

I wanted to ask advice on putting in some noggins to strengthen the floor as there will be a power rack and Olympic weights against the back wall. I’m not sure what the floor would hold in terms of weight but the joists are 58 x 240 I joists. I figure if the rack is close to the block wall I should be OK.

I’d also like a recommendation on which screws to get from Screwfix and also insulation to drop in there to improve sound deadening.

Picture attached. I want the floor to be as strong as so I’m not worried about crashing through the ceiling!

Cheers
Mikeinthemidlands

 

[flameport]

a power rack and Olympic weights against the back wall

How much weight?

I’m not sure what the floor would hold

Probably far more than you imagine.

Removing the chipboard and replacing with ply is almost certainly a total waste of time and money. It will also add weight to the floor, reducing the load capacity.

 

[foxhole]

Drop a weight on chipboard and it will go straight thru , so ply is a good idea . Place any heavy weight close to wall and you should be fine . Insulation under floor will have no effect as the sound transmits thru the timber . Thick rubber tiles would help avoid some damage to the floor.

 

[Keithmac]

Decent quality thick undlerlay and crarpet would be a good idea on top.of the ply.

 

[mikeinthemidlands]

Thanks for the replies guys. The rack is about 100kg, 150kg of weight then me so maybe 350kg? There will be no hitting the floor or anything as most exercises will be within the rack which will be bolted to the floor.

Should I include noggins?
Is it worth putting in acoustic insulation. Just thinking about music and general noise from weights.
Which screws should I use? 2 1/2 8s Spax from Screwfix OK?
Should I also glue the boards down? I don't the dreaded creaking/squeaking like I have with the chipboard.

Thanks
Mikeinthemidlands

 

[SFK]

Mike,
I am a DIYer, so listen to the others before me. :>
But when I last did a flexing bathroom floor in an old Victorian house so the floor would be stable enough to be tiled:

1) I put noggins in across middle of floor and was impressed how much more stable the floor became.

2) I used plyboard and I put noggins across where edges of plyboard was to stop it sagging.

3) I put in rockwool as a thermal and acoustic insulation. I did this because I could afford it, and felt that I would be more upset/frustrated later if I did not and then could easily hear people on toilet.
BUT I did this in the full knowledge that:
- I have no idea if it has actually made a difference as cannot compare before and after.
- I know that a lot of noise passes via timber joists and so filling between (as I did) does not make a massive difference.
- I know that better sound proofing comes from stopping noise in first place (ie why underlay and carpet works so well).
- But happy I did it as I spent what I could afford and 'believe' it has made some improvement.

4) I used "spax countersunk flooringscrew4.5x60mm" because they had the extra screwy bit and claimed they held floor down tightly. I think i put them every 15cm.
https://www.screwfix.com/p/spax-tx-countersunk-wirox-flooring-screw-4-5-x-60mm-300-pack/88716

5) I did not glue floor down.

So far floor has become the most solid floor in house.
Hope this helps,
SFK

 

[tony1851]

Would certainly replace the chipboard with plywood, and if you could glue it down in addition to screwing, it would make for a more rigid floor.
Sound-wise, you will not have much success, as most of your sound will presumably be impact sound rather than airborne, but any addition to the weight of the floor will help. But with a timber floor, you are fairly limited in the amount of weight you can add.

 

[mikeinthemidlands]

Hi guys

Please could you recommend screws and glue from Screwfix for the job? I need to buy it ASAP to do the job on the weekend.

Cheers
Mikeinthemidlands

 

[SFK]

Mike
1) "spax countersunk flooringscrew4.5x60mm" because they had the extra screwy bit and claimed they held floor down tightly. I think I put them every 15cm.
https://www.screwfix.com/p/spax-tx-countersunk-wirox-flooring-screw-4-5-x-60mm-300-pack/88716

2) I did not use glue, but if I was going to I would use PVA heavily applied to top of joist with a cheap paint brush:
https://www.screwfix.com/c/building-doors/pva-sealers/cat850040

SFK

 

[mikeinthemidlands]

Hi guys

Is there anyone that can give me an idea of the loading capacity of my floor now that I have finished it. There's finnjoists 58 x 240 x 4100m spaced at 600 centres (end two joists are 400 centres) sitting on joist hangers. I've put down 25mm plywood in half the room where the power rack and Olympic weights will be. Left the other side in 22 mm chipboard. All ply boards have been glued with D4 and screwed with Spax 4.5 x 60mm screws every 100m along joists.

The power rack and weights will be against the wall 1.2m x 1.5m and this is where all the weight will be. Maybe 400 - 500kg including all weight, equipment and maybe two people at most. The weight would be spread over two or three joists.

Thanks guys!
Mikeinthemidlands