Insulation on Block and Beam Floor

[gillpsimonb]

We are about to insulate a block and beam floor with 100mm celotex and then put 65mm screed on top of that. Bit worried that the block and beam floor is a bit uneven and that the insulation may move when laid on top of it ... and crack the screed. Am I worrying unnecessarily or do I need to make the block and beam floor more level before putting the insulation sheets down.... and if so how is this best achieved ? Thanks

 

[freddiemercurystwin]

Why isn't the BB floor level? How un-level is it?

 

[gillpsimonb]

It's just uneven - the rain sits in puddles on it in the lower patches - so not level all over.

 

[freddiemercurystwin]

How deep are the puddles? 3mm or 3cm or 3"?

 

[gillpsimonb]

just worried that the sheets of insulation may not lie flat - so may move especially when the screed is actually being put down on it.

 

[gillpsimonb]

How deep are the puddles? 3mm or 3cm or 3"?

maybe a difference of about 1 - 1.5 cm

 

[freddiemercurystwin]

Over what distance?

 

[freddiemercurystwin]

Got a photo?

 

[gillpsimonb]

high point is beam low point is the block - generally

 

[gillpsimonb]

Will have a look for a photo

 

[gillpsimonb]

 

[gillpsimonb]

Not a very good photo - sorry

 

[gillpsimonb]

Can we use some sand to level it up maybe ?

 

[freddiemercurystwin]

I meant with the rainwater!

Is it really up to 15mm? Stick a long level on it to check.

You can cut your insulation Union Jack style to allow it to fit better but depends on the undulations, don't forget the polythene sheet over the top of the insulation.