Is it worth adding a thin layer of floor insulation

[knockerchoppington]

I'm looking into laying floorboards in my lower ground floor flat where room height is a bit of an issue. At the moment it's a concrete floor. I was thinking of adding 12mm of celotex followed by 18mm tongue and groove chipboard and then 18mm wooden floorboards on top of that. My question is whether it's worth adding the 12mm of celotex. Will it make any difference to taking the chill off the floor? And will it prevent heat loss through the floor?
I've just ordered 3 radiators so don't want to go the underfloor heating route.

Thanks

 

[WoodYouLike]

How do you plan to install your solid wood floor on whatever insulation you use? If possible, stay away from chipboard.

How level is your concrete floor?

 

[knockerchoppington]

WoodYouLike,
I was thinking about floating wooden floorboards so as to avoid fixing it to chipboard.
I'm having the floor leveled with floor leveling compound.

Thanks

 

[freddiemercurystwin]

12mm is a bit weedy, it will make a difference but can you not go for 25mm instead? Only another 13mm?

 

[knockerchoppington]

freddymercurystwin
I have to floorboard the entire ground floor and there is a passageway where I almost have to lower my head to get through. I think even another13mm might make a lot of difference, for me at least
Perhaps I could go down to 12mm on the chipboard. Would that by sturdy enough to support the floorboards and traffic?

 

[WoodYouLike]

WoodYouLike,
I was thinking about floating wooden floorboards so as to avoid fixing it to chipboard.
I'm having the floor leveled with floor leveling compound.

Thanks

So you could install directly on the concrete if you use a thick combi-underlayment type (like Timbermate Excel) instead of adding the celotex and the chipboard?

Note of caution in regards of 18mm solid Oak flooring: if your boards are rather narrow (90 - 100mm) or have many short lengths (the solid "offers" of various DIY-sheds come to mind - 300-1200mm long) you might not be able to install your floor floating. If that's the case, replace the chipboard for plywood and fully bond the floor to the plywood.

 

[freddiemercurystwin]

Over to WoodYouLike for that one, she's the expert on that.

edit: damn she's fast!

 

[WoodYouLike]

Nah, not really - was typing me reply when "knocker" was typing too and I hadn't even seen his reply to you.

Why do you think you need that much insulation?

 

[knockerchoppington]

So you could install directly on the concrete if you use a thick combi-underlayment type (like Timbermate Excel) instead of adding the celotex and the chipboard?

Note of caution in regards of 18mm solid Oak flooring: if your boards are rather narrow (90 - 100mm) or have many short lengths (the solid "offers" of various DIY-sheds come to mind - 300-1200mm long) you might not be able to install your floor floating. If that's the case, replace the chipboard for plywood and fully bond the floor to the plywood.

What sort of thickness do you recommend, and do you suggest laying the floorboards straight onto the combi-underlayment?

Also re the note of caution. When you say fully bond does this mean glue?

Thanks again!

 

[WoodYouLike]

Fully bonding the wood floor to the (sub)floor with flexible adhesive.

If your concrete floor is level and you need a bit more insulation the Timbermate Excel is 3.6mm thick and includes a dpm. You install the floorboards on top of the underlayment, glueing all T&G's correctly.

 

[knockerchoppington]

Although I don't have any insulation under my concrete Timbermate excel seems to be the product I'll be needing. I'm surprised that such a thin product has great thermal properties. Thanks for your great advice!

 

[WoodYouLike]

Here's one (of more) article we've written in regards of underlayment:

Type of underfloor is type of underlayment

 

[knockerchoppington]

Has anyone tried Depron in this situation? It appears to have excellent thermal qualities...

 

[mointainwalker]

I'm puzzled by this comment. What's so good about it ?

It appears to have excellent thermal qualities

[/quote]

 

[knockerchoppington]

I'm puzzled by this comment. What's so good about it ?

It appears to have excellent thermal qualities

[/quote]

I came across while researching thin insulation. Turns out it's often used with underfloor heating, so not really what I'm looking for. Timbermate Silentfloor Gold seems to be the best option I have.