Advice needed please....

[vovo]

I personally wouldn't use chipboard and would just put 25mm WBP ply onto the joists (With noggins)

You don't need to prime the face of the ply. If you were using the ply as an overboard, you would prime the bottom and edges of it, but not the face.

You don't need insulations boards, but, they do what they say on the tin. It will be more economical in the long run. Ply isn't too bad for UFH. Uninsulated concrete is the worst and would definitely require insulation boards.

Thanks Matt - I'll skip the insulation board.

Can you recommend what kind of prime to buy/use? Is it for water resistance?

Also I need to find out how to make noggins..

Cheers.

 

[Matt]

Thanks Matt - I'll skip the insulation board.

Can you recommend what kind of prime to buy/use? Is it for water resistance?

Also I need to find out how to make noggins..

Cheers.

If you want to waterproof it, then a waterproofing membrane or paste would be better. The primer is just to help the adhesion between the ply and whatever is under it. (Because you are not overboarding, you don't need to prime).

 

[Paddyh2]

You don't need to prime the face of the ply. If you were using the ply as an overboard, you would prime the bottom and edges of it, but not the face.QUOTE]

I always prime the top. If anything it helps the adhesion when sticking the mat down. Any dust and nothing sticks.

 

[Daz]

I think you should only use a heating element of max 100 watts if you set it on ply (Uheat will confirm or deny this), but you can use a 160 or 200 watt element if using insulation boards.

I think Aaron mentioned this to me when he was working there.

 

[vovo]

Can anyone recommend where to buy 25mm plywood please?
Have a quick look and they seem to be really expensive 🙁 about £50 per sheet, and I need 2 for my small bathroom!

 

[kilty55]

if you have access to a builders merchants you will get it cheaper than that mate

 

[Matt]

I think you should only use a heating element of max 100 watts if you set it on ply (Uheat will confirm or deny this), but you can use a 160 or 200 watt element if using insulation boards.
I think Aaron mentioned this to me when he was working there.

Hmmmm, this is not something I have heard. I know our UFH supplier say that 150w mats are suitable for ply.

 

[vovo]

if you have access to a builders merchants you will get it cheaper than that mate

Which builders merchants do you guys normally go to? Do I need a tradecard for that?

I can see that Selco has the 25mm for £44.19 (excluding VAT) - is the price reasonable or where can I get them cheaper?

Thanks.

 

[Richardk]

Thanks for quick reply - I'm just worried that if require an insulator board,and UFH on top the floor will be too thick.


The other question is Richardk was suggesting the following:

1. Replace old floor with 18mm weyroc (chipboard) screwed to beams.
2. 6mm WBP ply screwed every 200mm to flooring
3. prime ply with acrylic primer

Just wondering why do you need a 18mm weyroc + 6mm ply , why not a thicker layer of ply?

And what's the purpose of prime ply wiht arcylic primer? Is it for insulation purpose, if yes, can I just prime my 25mm ply, and not having the insulating board?

It was another poster who suggested 6mm ply, I was suggesting backerboard. I prefer to keep wood out of the equation.

 

[vovo]

Just checking again if anyone could recommend where to get cheaper 25mm plywood? Tried looking online but not found anything thanks