SIPS U values

[Goggs]

Just sent out my architect drawings to 4 well known SIPS manufacturers for quotes. Its a 340m2 house, barn type structure. I have 2 quotes back, similar pricing but quoting very different panels. One has quoted 150mm thick panels for the walls and roof but they are polyurethane sandwich with a U of 0.024 w/m2 which seems incredibly low. The other is 194mm for the walls and 219mm for the roof but polystyrene sandwich with U of 0.18 w/m2 and 0.15 w/m2 respectively. The U value for the polyurethane SIP seems incredibly low and it is the thinner panel. Anybody got any experience of polyurethane vs polystyrene panels?

[A_L]

Hello and welcome,

 

9 minutes ago, Goggs said:

they are polyurethane sandwich with a U of 0.024 w/m2 which seems incredibly low.

 

That number is most likely the thermal conductivity of the polyurethane not the U-value of the whole panel. The U-value of a 150mm panel is likely to be a little below 0.16W/m².K

[Goggs]

Thanks and glad to be here. From what I gather PUR has a better thermal performance than EPS resulting in a thinner, lighter panel. I can imagine that PUR panels are more difficult to manufacture compared to EPS. As long as the thermal values are comparable, thicker panels are not a bad thing, just need to take into account transportation and handling.

[SuperJohnG]

It's exactly as you say, the PUR panels have a lower U value for the same width of panel. 

 

However most EPS supplier just have thicker panels. 

 

I have 169mm wall panels with 219mm roof panels, EPS from SIPSECO.  

[Goggs]

Sounds good. It is SIPS ECO that have quoted the thicker EPS panels. What was your experience with SIPSECO from a service delivery perspective?

[SuperJohnG]

11 hours ago, Goggs said:

Sounds good. It is SIPS ECO that have quoted the thicker EPS panels. What was your experience with SIPSECO from a service delivery perspective?

I can drop you a pm with some details. 

 

Panels quality good, everything else needs more details.