SIPs no, not pensions

[Tim Lamb]

Does anyone have experience or views on using Structural Insulated Panels for a two storey chalet bungalow extension?

Subject to planning, I may have such a project in prospect. The rest of the building is brick clad timber frame and referred to as the *cricket pavilion* by my wife!

One immediate benefit according to the Kingspan site is the potential extra floor space for the same footprint. (If timber clad) For a greenbelt site, the planners are wedded to below 40% extra:-(

They also show pitched roof structures without rafters although not hugely heavy tiles.

Thoughts?

[dennis]

They are very quick at producing a weather proof structure which is a big advantage for DIY.

[Andy Burns]

I've looked at them (only for "what if?" projects, rather than concrete plans) they look impressive, but then they only seem to have a 50 year rated life ... will houses built with them become prefabs MkII?

[tabbypurr]

Will they ever manage to reach that 50 years? How many will collapse without obvious warning as complacent homeowners don't realise how fast they're rotting? It seems evident they have limited life, and what the consequences of that are.

NT

[spuorgelgoog]

Having seen them demonstrated at a show I'm reluctant to built with something that can almost be cut through with a breadknife.

I'm not worried about it falling down, but they don't seem particularly burglar-proof.

Owain

[Andy Burns]

For an all SIPs construction, the heating requirement seems to be pushed towards MHVR systems, if the existing part of the building has a conventional heating system, might that lead to a 'conflict' of requirements?

Depends whether you clad it with timber, render it, hang tiles or build a non-structural brick outer skin round it ...

[Tim Lamb]

Currently microbore conventional gas fired radiator system. If practical; squeezing in enough insulation, the idea is to rip that out and go for wet underfloor throughout.

Existing has a brick skin but feather edge timber would match other buildings on site and be within my skill set.

>

[Andy Burns]

I've always thought I'd tend towards wet UFH in a self-build, but that doesn't seem to be "the way" with SIPs houses ...

[Tim Lamb]

A friend used it on a *grand design* in Suffolk. Air source heat pump. Seems to work although 24 hour occupation may hide issues.

>

[dennis]

The same as timber framed houses will collapse after 50 years?

[Tim Lamb]

In message , dennis@home.?.invalid writes

The one I am currently in is Victorian! Feather edge boarded for most of its life but now insulated, boarded and rendered. During the renovations, it was interesting to see how generations of Rats had gnawed their way past 4"x2" uprights! Woodworm have been and gone etc.

The niggle in the back of my mind is unforeseen deterioration of anything plastic with time. Witness the sticky plastic scissor handles, sticky worktops etc. I replaced a set of plastic meter wheels on a seed drill to find they collapsed in a sticky mess after only 10 years!

[Andy Burns]

Solid timber is one thing, but how long will the glue last in OSB? How long with the foam stay autohesively bonded to the OSB?

The 50 years figure quoted may be someone's best guess at the above ...

[tabbypurr]

Buildings are funny things. You can design new methods to cover all the bas es, only to find that half the time they've failed to address some key thin g and fail. I'd be a bit wary of new unproven technology, particularly when it appears as unreassuring as SIP. OTOH it has its upside for the OP, but I'd just not trust it'll be habitable & mortgageable down the line.

NT