minimum screed and concrete woes

[syne]

Well, after much rushing about and what I thought was enough preparations a few unexpected things have happened . Primarily the ufh pipe in a few locations have appeared just under the surface of the concrete floor slab. 

I initially planned on having them 40mm below the surface then using a thin self levelling with a bamboo floor on top to meet my existing floor levels but in a couple of places I can now see the pipe runs or 'shadows' of pipes so Im going to have to assume the lot is somewhere close under the surface of the concrete now. 

raising the ffl a bit isn't a problem as the rest of the house can be raised to suit but I'd like to keep it to a minimum amount. 

What is the thinnest thickness of screed/self leveller amount I can feasibly get a way with?  

 

[Gus Potter]

Don't worry too much.. it is what it is.

 

There are plenty folk on BH that have spent ages planning heating loops .. but on site when the pressure is on pipes get lapped over and some have little cover. Life is not ideal!

 

Think about this another way..it's not 70 deg C water you are pumping in through the pipes more like 35 - 45 deg tops.. about the same as our body temperature give or take.

 

Ok you have some bamboo flooring. Now imagine you have some patio doors and the sun has been streaming in all day on the floor.. how hot will that get locally?

 

I have a big floor on UF.. but floated it rather than glued it down.. it moves about but is still a happy floor.

 

Don't panic.. just turn it on and enjoy. Bamboo is very forgiving... think about the climate it grows up in.. humidity, big changes in temperature and so on.

 

What you do need to watch out for is this. In the winter when the UF is on.. the moisture content is low so the floor shrinks. BUT the biggy is when the heating is off in the summer the moisture content will rise and the floor will swell a lot that funnily is when you get the visible problems at the end of the summer.. and folk blame the UF. Leave a gap round the edges of the flooring for the movement.

 

 

[syne]

Thanks gus, good points reassuringly made. 

Your right the sun on the floor through the patio doors does produce a really warm spot.

 

Did you use a Cork fillet on the perimeter edge?

[saveasteading]

3 hours ago, syne said:

reassuringly made. 

I'm not so sure. Not so sure @Gus Potter is being reassuring either. Bamboo is a low density wood (grass) and there is a lot of resin  in the product. It could move a lot.

I'd certainly use a cork fillet. I think I would also put a bit of latex down to cover the pipes.

At the expense of restricting heat flow, should the floor have an underlay?

I have not done homework on what I've said, so you should.

[Gone West]

We didn't have UFH and our bamboo flooring pulled back from the edges in the summer, in the main bedroom, if the sun shone on it for any length of time. The solution was to close the blinds a bit.

[syne]

pige -cat- ons..

 

I'm definitely going to be putting a self leveller down, Knauf N430 to be precise. looking at 20mm worth. That would make the max depth of any pipe 60mm and the minimum depth of some pipes 20, 

I was planning on a floating bamboo floor with an expansion gap on the perimeter and the 20mm thick skirting above the floor.  I've used cork edge on a laminate floor before and it worked well, would bamboo be likely to contract more than 20mm from each edge...?

 

[saveasteading]

57 minutes ago, syne said:

likely to contract more than 20mm

My hunch is no. Especially if you expose the materials to the air of that room, before laying.

I'd be more concerned with expansion but the same applies.

 

Is the product laminated? So like plywood?