Getting confused with TF, SIPS , block and brick.

[Stonehouse]

Hi hoping for some simple guidance. House was initially planned as extension / Reno but now been submitted for new build 

 

Planned as block and brick but now options are open. Heard lots about SIPS and TF so have been getting quotes. But now getting confused and read here some don’t like SIPS. 
 

I have a builder and I won’t be hands on. So won’t be on site every day checking everything. I was aware factory built SIP/TF might be more expensive initially

 but would save on labour

 

my thoughts were with SIP/ TF I would be able to achieve better air tightness compare to block and brick. Am I correct? 
 

Secondly I am now getting confused with SIP and TF. How do they differ ? If TF is provided with insulation then is this not a SIP?

 

i know there are different types of insulation. Some on here don’t like PIR. Is there a reason?

 

[Redbeard]

Welcome. 

 

OK, PIR. It is relatively inexpensive in £ for R value but, if you don't like plastic, it's plastic. If you are trying to steer clear of fossil fuels then arguably don't insulate with oil-derived products. On the other hand if your better insulation  with oil based products gives you lower heat-load overall then you are reducing your dependence on the grid.. It's not simple. For me it's a gut feeling. I try to avoid plastic insulation when I can. Others will have heard reports of the Grenfell enquiry and resolved to avoid PIR. Again, gut feeling, but dig in deeper and you can see the circs were pretty specific. I have one 'tight' bit where i will either sacrifice insulation value or use PIR or similar. Still mulling. Lots on here will have gone through the same thought processes so may be able to offer some short cuts.

 

If you are doing TF you could, for example, use a system which blows in cellulose (recyc newspaper) insulation - reduce the plastic, good for air-tightness. Lots on here will rate it. OTOH if you are really tight for space and building 'with a shoe-horn' then maybe PIR is admissible. The final arbiter is you.

 

Again, I am not experienced with SIPS but I suspect they are designed as stressed members, where the OSB is part opf the load calc, whereas TF takes all the load on the frame and cladding etc is just expedient.

[nod]

I’m currently doing the plastering and rendering on a small site of self builders 

While TF are much quicker to get watertight I’m reliably informed that it’s working out about 30% ish more for TF to watertight After that the costs for materials and labour are the same 

It’s personal choice 

[SteamyTea]

The difference between SIP and TF is how the structural loads are distributed.

 

Structural Insulated Panel

Timber Frame

 

There are many different ways to design with each.

[saveasteading]

Sips is trendy. Sips is limiting re geometry.

Use what the local builders are happy with, whether timber frame or masonry.

Or buy in a timber frame as a kit.

TF is not expensive if kept simple.

[SteamyTea]

The combination of TF and blown cellulose insulation is very good for both thermal and sound transmission.

Possibly the lowest mainstream embodied energy and carbon construction.

(It is very easy to fudge embodied numbers, so take all of them with a very large punch of salt)

[joe90]

11 hours ago, Redbeard said:

if you don't like plastic,

I don’t, I only used it under a concrete floor as nothing else supports concrete floors.

16 hours ago, Stonehouse said:

my thoughts were with SIP/ TF I would be able to achieve better air tightness compare to block and brick. Am I correct? 

Not necessarily, I built brick and block with 200mm cavity filled with mineral wool. The airtightness is down to attention to detail and my result was good. I am not convinced on the longevity of air tightness sticky tape . I like brick, I don’t like render (less maintenance and looks nicer in my opinion).

however I like cellulose insulation for it’s being a non oil based material and very good sound proofing level.

[Stonehouse]

Thanks everyone very useful and think I understand it a bit better now. Never paid attention to them at building shows as we were not considering it
 

So with timber frame I have some flexibility of what insulation I use.  
 

Was my builder who suggested getting some TF / SIPS quotes. Massive variation in prices I’ve found so far. Plus need to really look into the details on what’s included with each quote.