Workshop flooring - Advice please

[Losos]

Well I am in a fix, I was all set to get a hardwood floor laid direct onto the concrete slab when I've been told the wide temperature variations in my shop will not allow this. The flooring firm has suggested joists 400mm apart with chipboard (They call it multi-purpose board) on top.

Will this give a good 'solid' floor, I'm planning the usual sorts of machines and I'm a bit worried that it won't be solid enough. Has anyone done this with their floors? What spacing of joists is usual? What thickness of board should be used?

Maybe I should add that we get -20 C in winter and + 25 C in summer. I will of course be heating the shop, but will not necessarily be using it every day.

Welcome any comments from anybody please

 

[PowerTool]

400mm joist spacing is fairly standard,but the big problem with chipboard is that if it ever gets wet,it tends to swell and break (although it does seem to be the preferred flooring in modern houses - guess it's cheaper rather than better..)
Personally,prefer plywood to chipboard - looks better,more moisture-resistant, and stronger.

Why can you not have a real wood floor?
If this is because of expansion,would using tongue-and-groove and leaving an expansion gap around the edge be good enough?

 

[ProShop]

Losos,
I'm afraid the flooring company are right about laying straight onto concrete, especially if it's building is similar to a garage ie single skin walls big doors etc.

The 400mm spacing for a workshop IMHO is to big, especially if your having heavy machines. I would certainly if your building is as I mention above forget using chipboard. you could use shuttering plywood sheets (we can get over here in the UK 25mm thick sheets, they make an incredibly strong floor) and then if you wish put your harwood on top. that would make a very solid floor indeed.

Wood straight onto concrete will draw the moisture up into the floor causing it to swell and the associated problems, by using joists you have an air space to allow the wood to breathe. I would strongly advise a membrane onto the concrete first of all.

Hope this helps

 

[Waka]

Losos

You will be ok with that distance of spacing, my floor has similar joist spacing and it takes all my machinery no problem. Going down the joist route allows youto pack insulation between the joist and beleive me that really makes a difference.

 

[OLD]

Have you considered fitting insulation between the joists and also incorporating a damp proof membrane for a warm dry floor.

 

[ProShop]

Losos

You will be ok with that distance of spacing, my floor has similar joist spacing and it takes all my machinery no problem.

Sorry to disagree, if I remember correctly Losos has some Felder/Hammer machines coming his way soon and they are seriously heavy. The weight/ load bearing at 400mm centres figures don't add up.

 

[Waka]

Not sure what the weight of the machinery Losos is buying, but my Woodford 807 comes in at 280kg and so far I've had no problem with the floor and this machine gets moved around quite a lot.

 

[Woody Alan]

If it's of any help I put a DPC heavy guage plastic sheet over my conctrete, then fibre board about 8-10mm thick as designed to go under laminate floor ,then moisture grade chipboard I've been very happy with it and had no problems that I know of. Oh and it seems to be warm enough too.

Cheers Alan

 

[Anonymous]

FWIW I painted my floor with rubberised sealant, going 4" up the walls all round to get above the dpc, and I laid a 22mm thick chipboard floor on top with 600 spacing then painted it with floor paint. It's warm, solid enough and has been down for 2 years with no problems so far. The building was previously really wet in winter, too, but it's stayed nice and dry. I used 600 spacing simply because that was how many 2x4's I had lying around at the time! Even with the tablesaw on top it's fine.

 

[Scott]

The building was previously really wet in winter, too, but it's stayed nice and dry.

Brian

Can I ask how wet? Was it badly damp or actual water? I have a problem with dampness coming through the workshop floor because there's presumably no damp-proof membrane under the concrete (used to be a cow shed). At it's worst it's enough to make small amounts of standing water in two or three of the channels that are moulded into the floor

I have -12 in winter and +35 in summer so same problem as Losos

 

[Anonymous]

Scott:

The floor was cracked across its width, and there was a huge crack up one wall. In heavy rain I had standing water and a dripping wall

I did a rough scrape of all the cracks, filled the worst of the floor crack with cement (1/2" gaps to fill in places) with a waterproofing additive, and I used a hard glue to fill tha wall crack (Unibond "Mega Grip" - available from Jewsons I think), Finshed it off with one coat of bitumen paint (very thick over the crack and around the edges) and a topcoat of driveway sealer (It was lying around so I decided to use it up!). Dry as a bone now.

Incidentally, I also had a crack in the roughcast on the outside of the building. Filled that with Mega Grip 4 years ago and it's still holding.

 

[Scott]

Brilliant! Thanks for that Brian

 

[Losos]

Thanks for all the info guys.

John - Haven't placed the order yet but more or less decided on the Hammer - Yes they weigh a lot

The wall are single skin but they are ****** thick (About 900mm) and yes there will be a big double door at one end. I will be heating the place of course but not every day, I think that's where the problem is.

I'm interested in the idea of fibre board direct onto slab (With a membrane of course) and chipboard on top of that.

Otherwise I'll ask the flooring firm to quote for 25mm plywood.

Thanks again for answers from you good guys

 

[thomaskennedy]

I'm using OSB on my floor, its Exterior grade, and i've had it on half of the floor so far with a band saw and P/T ontop, and everything seems fine.

It might not be the nicest to look at, but im planning on covering that with some birch ply, or similar

Ta, Tom