Using sips as dry lining

[Aaron Cabrele]

Hi

Long time lurker... first time poster! Hoping you knowledgable chaps can point me in the right direction.

We have recently been through the process of design, planning and engineering drawings for a 2 story side extensions (~£2500) only to find that estimates for the work a far in excess of our expectations (and the £/m averages). We would simply not get our money back or even close.

While we deliberate on that, we have decided to make a start on alterations to the existing house. I'm refurbing the downstairs shower room now and next up will be kitchen.

The house has an existing single story extension on the back, obviously done some years ago. It is a single skin block work construction. Seems to have started life as a sun room with polycarbonate roof then been divided in half. The half to the back of the kitchen has a "proper roof" now and internally looks like any other room.

I'm following a minimum effort maximum gain principle with changes here. I'd like to line the inside with SIPs panels to provide better insulation and improve the structural integrity of the single skin wall, ultimately to bear a new roof with a lantern (~250kg) which stretches all the way across the back rather than just the kitchen.

Does this sound plausible / sensible? I have considered knocking the whole lot down but £££ and also means re fisnihing the external render etc. Effectively what I'm suggesting is that I build out a sip/block wall in reverse. The corner details I can construct before placement as most of the back is patio doors... it's almost an orangery. My only doubt is how I would fix the sip to he wall since it would inaccessible to use U brackets. Dot an dab springs to mind, or could screw through the whole panel I guess.

Thanks!!

 

[freddiemercurystwin]

No it doesn't make any sense. They would be more expensive not to mention the question as to how you would manage to get wall sized panels into the room. Just build an insulated stud wall inside as you would in a barn conversion.

 

[Aaron Cabrele]

Hi

Thanks for the reply. I had considered that too, but I liked the sips speed, efficiency, simplicity and structural strength.

Access isn't an issue, 30ft of side access and large patio doors. Panels are only 8x4 - I'm talking about the sips ecopanls you fit together with splines and can be handled by two.

Cost I worked out to not be dissimilar by the time you have costed in insulation and time. About £800. Because of the patio doors there is only about 23 linear foot of wall.

 

[Aaron Cabrele]

So let's say I went the stud route. Any special consideration for studwork design for supporting the roof? The space is 2400 x 7200mm. The lantern will be 4000 x 1500 leaving a small amount of actual solid roof around it.

Across the back 7200mm are 2 sets of 2500mm sliding doors which we will replace with newer units, perhaps bifold but bottom hung.

On one 2400mm projection there is a 900mm square window.

So I would do 400mm centres of 2x4 with a double top plate, single sole plate and probably some cross bracing with metal strips. Over the doors 2 9x3 beams bolted together, one over the new stud work and one over the existing block work. Would probably also use some metal strips to help strengthen the existing wall, along which can fit the wall ties to the studwork.

The floor is concrete by the way.