Roofmate or XPS

[foxinthehouse]

Hello everyone
I have just had the floor of my wooden lodge insulated. The lodge is on wood piles. It is a suspended 18mm flooring grade chipboard floor, open underneath on all sides and the floor is very cold in the winter. The builder quoted 60mm Roofmate and a vapour barrier, but has installed 60mm XPS and no barrier. When I questioned the workers, they say this is the best solution as there are grooves in the xps to stop condensation and a physical barrier is not required. They have filled any gaps with expanded foam.
Has anyone any comments on the difference between roofmate boards and Danopren XPS TL (blue, grooved on the floor side) (I'm in Portugal).
The job looks good and I have no problems with the result, except I do not know the difference in insulation value between the two.
Grateful for any help.

 

[^woody^]

Polystyrene is the least efficient of all the foam insulation boards, and styrofoam (roofmate) is more efficient for any similar thickness.

A refund of the cost difference will go towards offsetting slightly greater heat loss

 

[foxinthehouse]

Thanks woody, I thought Roofmate was EPS which I understand is similar to XPS except in the manufacturing process.
Maybe I'm wrong as I have zero knowledge in this area, perhaps someone can clarify the difference between the two. Danopren is not widely available in UK yet so I have included a picture of the product.
Don't you just hate it when specifications get changed without consultation. Makes you wonder why the change.

 

[^woody^]

Roofmate is made by Styrofoam, and Styrofoam's products are a specific manufacturing process to normal polystyrene (ie XPS).

Unless Styrofoam are making this Roofmate from a normal XPS process (doubtful but you never know), then it will be their own stuff and so of better insulation quality than normal XPS.

As a general guide, XPS is white. Anything else that has a colour tends to be better than bog-standard XPS

 

[endecotp]

http://www.eurofoam.pt/es/eurisol-xps-tl.php says Danopren TL 60mm is 0.034 W/mK.
http://building.dow.com/eu/gbr/en/products/styrofoam/roofmate.htm says roofmate SL-AP is also 0.034 W/mK - though it suggests that the thinnest boards are 100mm if I've read it correctly. Perhaps this is why you've got the Danopren?
It looks to me as if neither is "bog standard" XPS.
I don't know about the vapour barrier / condensation issue.

 

[foxinthehouse]

Many thanks endecotp, That info is very helpful, and I've gone to the links you gave which has somewhat settled my concerns. I spoke to to Danopren today here in Portugal and although I can't speak much Portuguese, and the person I spoke to spoke limited English, we did establish that the builders have used the wrong product, although it would seem the slots on the board are too small to cause any air flow and heat loss. (hence the same SL-AP value). As Roofmate and Danopren seem very similar products I guess I will consider the change in materials acceptable. Thanks everyone for your help.