Fit floorboards to a concrete conservatory floor

[Magic94]

Unless you have somebody living under the floor of your conservatory

Mice? Toads?

Cheers
Richard

I thought it was noise upward into the conservatory

Thanks

 

[Magic94]

It was the site advertising the joist's that states 18 / 22 mm chipboard. The floor will be covered by carpet so the finish is not important.

Oh good grief. I think everyone here, myself included, assumed to wanted an exposed wooden floor. There's no point in fitting engineered wooden flooring, or floorboards, if you're just going to cover it all with carpet. Use 18mm flooring grade chipboard.

Cheers
Richard

Sorry I should have said it was to be covered by carpet I am glad you said that about the using the chipboard under the carpet I was beginning to wonder what I should do but now I can fit ordinary joist's as part of a floating floor and cover with chipboard. Thanks for your help

 

[ban-all-sheds]

I don't think you should float the floor over joists - it will drive you mad with the constant creaking. I don't think it's so dimensionally unstable that it needs to be a floating floor (but check on the flooring forum) - screwing it (not nailing) to the joists seems like a better plan.

And 18mm is bit thin, given how sh**e chipboard is these days. What's the joist spacing?

 

[3DGuy]

Use 22mm minimum P5 2.4m x 60cm T&G chipboard floors (18mm is ****e, I used some and put more wood over as it felt unstable with the flex), put something like celotex between the joists to insulate, make the joist spacing narrow. I would go for 300mm spacing or 400mm max between them, little more material and effort/cost but the long term solution will be rock solid. Creaking floorboards are awful and will get worse over time.

Get Spax Flooring screws with a twin thread and a gap between. It cranks the boards to the joists. Make the frame work rock solid. Don't use nails, Potential for the main frame you could coach bolt together, it wont move then. put some noggins between the long runs to help stop warping also.

Hope this helps,

PS get the chipboard if you do from a builders merchants, the DIY chains stuff is useless. We have a local buildbase here and the chipboard quality was miles better than the store ones. Used about 33x 8x4 sheets.

 

[geraldthehamster]

I don't think you should float the floor over joists - it will drive you mad with the constant creaking. I don't think it's so dimensionally unstable that it needs to be a floating floor (but check on the flooring forum) - screwing it (not nailing) to the joists seems like a better plan.

And 18mm is bit thin, given how sh**e chipboard is these days. What's the joist spacing?

Doesn't hurt to use 22mm, though I have 18mm and it's pretty stable. I've just thought about this again, though - my conservatory (which I didn't floor, but was already done when I bought the house) has 18mm T&G chipboard laid on top of 25mm polystyrene insulation, and it doesn't move at all. I reckon you could just lay T&G chipboard on top of whatever thickness of Celotex you required, and it wouldn't be going anywhere. How could it? That would save any farting about with joists at all.

Cheers
Richard

 

[Magic94]

I don't think you should float the floor over joists - it will drive you mad with the constant creaking. I don't think it's so dimensionally unstable that it needs to be a floating floor (but check on the flooring forum) - screwing it (not nailing) to the joists seems like a better plan.

And 18mm is bit thin, given how sh**e chipboard is these days. What's the joist spacing?

I was going to set the joist's around the walls with a gap to the wall of 10mm then space the joist's 16in apart and screw them together by sloping the screws into both. I was then going to screw the chipboard to the joist's I was going to lay a foil insulation onto the concrete and then between the joist's but I may change my mind I have found a product called Stryofloor which is an insulated chipboard that the flooring (carpet) can be laid onto, it comes in various thickness so I can raise the floor and with luck it will be easier to fit than joist's

 

[Magic94]

I don't think you should float the floor over joists - it will drive you mad with the constant creaking. I don't think it's so dimensionally unstable that it needs to be a floating floor (but check on the flooring forum) - screwing it (not nailing) to the joists seems like a better plan.

And 18mm is bit thin, given how sh**e chipboard is these days. What's the joist spacing?

Doesn't hurt to use 22mm, though I have 18mm and it's pretty stable. I've just thought about this again, though - my conservatory (which I didn't floor, but was already done when I bought the house) has 18mm T&G chipboard laid on top of 25mm polystyrene insulation, and it doesn't move at all. I reckon you could just lay T&G chipboard on top of whatever thickness of Celotex you required, and it wouldn't be going anywhere. How could it? That would save any farting about with joists at all.

I looked at Celotex but the info was not as good as the one I have found a product called Stryofloor which is an insulated chipboard that the flooring (carpet) can be laid onto, it comes in various thickness so I can raise the floor and with luck it will be easier to fit than joist's

Cheers
Richard

 

[FresnoBob]

Doesn't hurt to use 22mm, though I have 18mm and it's pretty stable. I've just thought about this again, though - my conservatory (which I didn't floor, but was already done when I bought the house) has 18mm T&G chipboard laid on top of 25mm polystyrene insulation, and it doesn't move at all. I reckon you could just lay T&G chipboard on top of whatever thickness of Celotex you required, and it wouldn't be going anywhere. How could it? That would save any farting about with joists at all.

Cheers
Richard

Most of our ground floor is constructed in this way, including a 5m x 4m living room, and it's rock solid. Only issue we've had (which has caused me to pull some of it up) was the subfloor being uneven which has meant in time the polystyrene and chipboard settled into a slight 'hump' (which probably wasn't as bad as I thought it was, but I'm a bit ocd about perfect levels). As long as the subfloor is even, it should be fine.

 

[Magic94]

Doesn't hurt to use 22mm, though I have 18mm and it's pretty stable. I've just thought about this again, though - my conservatory (which I didn't floor, but was already done when I bought the house) has 18mm T&G chipboard laid on top of 25mm polystyrene insulation, and it doesn't move at all. I reckon you could just lay T&G chipboard on top of whatever thickness of Celotex you required, and it wouldn't be going anywhere. How could it? That would save any farting about with joists at all.

Cheers
Richard

Most of our ground floor is constructed in this way, including a 5m x 4m living room, and it's rock solid. Only issue we've had (which has caused me to pull some of it up) was the subfloor being uneven which has meant in time the polystyrene and chipboard settled into a slight 'hump' (which probably wasn't as bad as I thought it was, but i'am a bit ocd about perfect levels). As long as the subfloor is even, it should be fine.

Yes I am not sure the concrete is perfectly level and I don't fancy using self leveling compound. The question is :- is it better to fix the joist's / beams to the concrete with them leveled with shims and cover with floor boards or float the joist's / beams and fix 22mm chipboard with a 10mm gap around which every I do it - which is best ? it seems easier to me to do it with floorboards as they are more manageable but what happens if / when the joist's fastened to the concrete expand?

 

[FresnoBob]

Yes I am not sure the concrete is perfectly level and I don't fancy using self leveling compound. The question is :- is it better to fix the joist's / beams to the concrete with them leveled with shims and cover with floor boards or float the joist's / beams and fix 22mm chipboard with a 10mm gap around which every I do it - which is best ? it seems easier to me to do it with floorboards as they are more manageable but what happens if / when the joist's fastened to the concrete expand?

I'm sure some of the more experienced folks will come along and tell me this way is rubbish.....but, I have levelled a similar floor in the past. First step was to lay some plastic sheet/membrane, just in case the concrete had any moisture in it, then lay the battens/joists down. I then added some cross pieces to form a sort of 'frame', screwed it all together, added the shims to raise it where it needed to be raised, laid the insulation in the gaps, and then screwed the board on top of that. I didn't screw the battens to the concrete.

I however used 25mm plywood, but I can't see it being any different for chipboard, other than using maybe a specific chipboard screw.

Like I say, the more experienced folks might say this way is rubbish, but it worked for me, the floor is level, doesn't creak, and has been rock solid for years.

 

[Magic94]

Yes I am not sure the concrete is perfectly level and I don't fancy using self leveling compound. The question is :- is it better to fix the joist's / beams to the concrete with them leveled with shims and cover with floor boards or float the joist's / beams and fix 22mm chipboard with a 10mm gap around which every I do it - which is best ? it seems easier to me to do it with floorboards as they are more manageable but what happens if / when the joist's fastened to the concrete expand?

I'm sure some of the more experienced folks will come along and tell me this way is rubbish.....but, I have levelled a similar floor in the past. First step was to lay some plastic sheet/membrane, just in case the concrete had any moisture in it, then lay the battens/joists down. I then added some cross pieces to form a sort of 'frame', screwed it all together, added the shims to raise it where it needed to be raised, laid the insulation in the gaps, and then screwed the board on top of that. I didn't screw the battens to the concrete.

I however used 25mm plywood, but I can't see it being any different for chipboard, other than using maybe a specific chipboard screw.

Like I say, the more experienced folks might say this way is rubbish, but it worked for me, the floor is level, doesn't creak, and has been rock solid for years.

I think I will use your suggestion unless there are any good reasons made against it. The plumber who fitted our shower put it on 22mm plywood ( I think he called it ships ply ) and I have used 6mm to cover the floorboards in the kitchen. Did your cross pieces include across the ends so the you had a complete square filled in with battens? The only reason I quoted chipboard was because it was T & G but plywood removes the problem of trying to fit the board and the groove when going near the wall.

 

[FresnoBob]

This photo isn't mine (I've pinched it off the interweb), but it's more or less the same thing.

 

[geraldthehamster]

I don't think you should float the floor over joists - it will drive you mad with the constant creaking. I don't think it's so dimensionally unstable that it needs to be a floating floor (but check on the flooring forum) - screwing it (not nailing) to the joists seems like a better plan.

And 18mm is bit thin, given how sh**e chipboard is these days. What's the joist spacing?

Doesn't hurt to use 22mm, though I have 18mm and it's pretty stable. I've just thought about this again, though - my conservatory (which I didn't floor, but was already done when I bought the house) has 18mm T&G chipboard laid on top of 25mm polystyrene insulation, and it doesn't move at all. I reckon you could just lay T&G chipboard on top of whatever thickness of Celotex you required, and it wouldn't be going anywhere. How could it? That would save any farting about with joists at all.

I looked at Celotex but the info was not as good as the one I have found a product called Stryofloor which is an insulated chipboard that the flooring (carpet) can be laid onto, it comes in various thickness so I can raise the floor and with luck it will be easier to fit than joist's

Cheers
Richard

Just to point out that I didn't write that final paragraph quoted above, about Stryofloor. I think someone mucked up the quoting tags when they attempted this post.

Cheers
Richard

 

[Magic94]

I don't think you should float the floor over joists - it will drive you mad with the constant creaking. I don't think it's so dimensionally unstable that it needs to be a floating floor (but check on the flooring forum) - screwing it (not nailing) to the joists seems like a better plan.

And 18mm is bit thin, given how sh**e chipboard is these days. What's the joist spacing?

Doesn't hurt to use 22mm, though I have 18mm and it's pretty stable. I've just thought about this again, though - my conservatory (which I didn't floor, but was already done when I bought the house) has 18mm T&G chipboard laid on top of 25mm polystyrene insulation, and it doesn't move at all. I reckon you could just lay T&G chipboard on top of whatever thickness of Celotex you required, and it wouldn't be going anywhere. How could it? That would save any farting about with joists at all.

I looked at Celotex but the info was not as good as the one I have found a product called Stryofloor which is an insulated chipboard that the flooring (carpet) can be laid onto, it comes in various thickness so I can raise the floor and with luck it will be easier to fit than joist's

Cheers
Richard

Just to point out that I didn't write that final paragraph quoted above, about Stryofloor. I think someone mucked up the quoting tags when they attempted this post.

Cheers
Richard

I did it wrong I had looked at Celotex and found the Stylofloor I must have done it wrong it was supposed to be my reply. The Stylofloor would raise the floor the 3 or 4 inches I wanted too. I think I will use battens similar to the photo above and cover with plywood.

Thanks