Seems a waist to insulate after all...?

[ollysfollys]

Hi all, i am ready to insulate the cony now as soon as the sparky has finmished the electrics and i have finished the plumbing of the 2 radiators.

I have been reading about the insulation for the single skin wall to the out side, not the house wall, now as i see it there is no point in insulating with anything less than 75mm polystyrene or even kingspan type insulation, or the plasterboard backed type, sorry keep forgetting the proper names.

If i use anything less than 75mm then it will still let damp through/condensation and as its a cont then it will ,oose mopst heat through windows and roof.

Am i correct in thinking all this?

I am on the edge of just plastering it all and to keep the damp out leave a window a jar and when its in use in the colder days turn on the 2 600x500 radiators i have.
If it needs it in the future i can insulate then, just it will take up way to much room to fit anything above 25mm realy and also be a waiotse of time and money?

please, your thoughts.

wayne

 

[big-all]

assuming its a conservatory[big glass thing ] you wont be able to use it without a hat and coat on
on all but the milder winter days

 

[ollysfollys]

assuming its a conservatory[big glass thing ] you wont be able to use it without a hat and coat on
on all but the milder winter days

So howdo full hight glass cony`s go on? oe even part glass part upvc con`ys?

Do you think the 2 rads wont be enough?

 

[big-all]

depends on size type d/g single/plastic it was worked out that the heat loss would be around 6 kw on a cold day
so iff your walls have maximum insulation you may be on say 5kw off heat loss
so 5kw will do little more than keep the chill off

 

[ajrobb]

Conservatories are not classed as living space, which is why you can build them without planning permission. They have to have so much glass to be classed as a conservatory that a high level of insulation on the walls (and floor) isn't going to be effective.

20mm of PIR should be enough to stop condensation on the walls.

 

[Richard C]

Why didn’t you use an insulated cavity dwarf wall? Now you’re going to have all sorts of problems trying to keep the damp out of the single skin wall. You cannot plaster damp walls & neither will it keep the damp out; it will just fall into a heap on the floor after a couple of months! Even the very best built & insulated cons. (& I have one) are little more heat efficient than your average garden shed; what type/thickness is the roof & the glazing? Have you insulated the floor?

Heat loss through cons windows & roof is pretty horrendous & they get expensive to heat from November through February. If you want year around use, build a garden room which is effectively an extension.

Just a couple of things for you to consider in order to comply with Building Regulations;
• The radiators in the cons must be capable of independent control & isolation from the main property system.
• Assume the new electrical circuit has been installed & signed off by a Part P sparky?
• To comply with safety regulations, glass must be toughened safety glass where appropriate; all the glass in my cons is toughened.
• You must maintain external grade door(s) between the cons & the main property or it won’t be classed as a cons but an extension with all that would entail (basically impossible)
• You don’t say what size your cons is but planning regulations are somewhat stricter than they used to be;
http://www.planningportal.gov.uk/england/public/buildingwork/projects/workcommonconservatory/

Conservatories are not classed as living space, which is why you can build them without planning permission.

Unfortunately that’s not true; see the link above.

 

[ollysfollys]

To answwer a few Q`s

The cony is 4.6m x 2.95m and at the highest oint 2.2m,

I insulated under the concrete with 50mm polystyrene.

I built the dwarf wall in single skin as to keep within planning permission of ` no deeper than half the house width` as it is an end cony and not at the rear. Also the single skin is it was when i bought it and it had been up for 8 years and when i pulled it down there was no damp etc.

It has the original exterior grade french doors still inplace for the BR.

Central heating i hope will be taken from the rad pipes direct, in the case for the BR i will fit a shut off valve.

still gets me why all the insulation but no need to use it, or much of it. If they are so cold anyway and loose loads of heat.......

Anyway, on insulation, i have popped into wicks today and found some 30mm slabs, not the rockwool type but a more solid type which i can fit with plaster board with a VP barrier to the wall by screwing it direct to the wall.

EDIT ( single skin as to save space inside also)

 

[Richard C]

I insulated under the concrete with 50mm polystyrene.

Polystyrene (if that's what you used) was a poor choice; you really need a high efficiency insulation slab such as Celotex, same thermal efficiency for only around ½ the thickness.

I built the dwarf wall in single skin as to keep within planning permission of ` no deeper than half the house width` as it is an end cony and not at the rear. Also the single skin is it was when i bought it and it had been up for 8 years and when i pulled it down there was no damp etc.

Personally I would have pinched some room from inside; minor loss of space for one huge improvement & you would not be having all this messing about insulating single skin walls. Still not too late to run up some 3" thermalite blocks with a 50mm cavity & insulate that; probably not much difference in cost/agro factor

Central heating i hope will be taken from the rad pipes direct, in the case for the BR i will fit a shut off valve.

To keep strictly within the regs fit TRV’s to each rad & isolation valves in the flow & return lines (inside the main property) & provision to drain the loop down in case you don’t use in winter.

still gets me why all the insulation but no need to use it, or much of it. If they are so cold anyway and loose loads of heat.......

It would be even worse if you didn’t bother; in terms of thermal efficiency, it just makes the most of the bad job that cons. are.

Anyway, on insulation, i have popped into wicks today and found some 30mm slabs, not the rockwool type but a more solid type which i can fit with plaster board with a VP barrier to the wall by screwing it direct to the wall.

Not a good idea to screw directly to the wall; you’d be better off using something like this; http://www.british-gypsum.com/produ...es/gyproc_thermal/gyproc_thermaline_plus.aspx
Unless it’s done correctly, you could have problems with all sorts of unhealthy & disgusting fungi growing behind there before too long, do yourself a favor & have a search/read back through the archive posts on the Plastering Forum where you will find many archive posts relevant to what you’re doing. Any of the regulars on there or in Building will respond if you come back with specific questions.

 

[ollysfollys]

I insulated under the concrete with 50mm polystyrene.

Polystyrene (if that's what you used) was a poor choice; you really need a high efficiency insulation slab such as Celotex, same thermal efficiency for only around ½ the thickness.



It was the choice i found the cheapest and the advice of most, at £3.50 a 8x4 sheet is better than around £25 and maybe that thicker but to save that much more when digging out.......

I built the dwarf wall in single skin as to keep within planning permission of ` no deeper than half the house width` as it is an end cony and not at the rear. Also the single skin is it was when i bought it and it had been up for 8 years and when i pulled it down there was no damp etc.

Personally I would have pinched some room from inside; minor loss of space for one huge improvement & you would not be having all this messing about insulating single skin walls. Still not too late to run up some 3" thermalite blocks with a 50mm cavity & insulate that; probably not much difference in cost/agro factor

Its a lot to loose around 6 inch of space all round on this project. Also again to loose so much room for so little heat gain i cant get around the benefit.

Central heating i hope will be taken from the rad pipes direct, in the case for the BR i will fit a shut off valve.

To keep strictly within the regs fit TRV’s to each rad & isolation valves in the flow & return lines (inside the main property) & provision to drain the loop down in case you don’t use in winter.



Well on this point i have got the TRV`s and bits already, but as its a whole lot of work to fit it all and get low out put from the 2 rads at only 800w towards.....i bet you say something here, towards a LPG wall heater at the same cost and LOADS easyer to fit and free to run i am going to seriousley going consider one, i work for a Calor gas agent so know al the ins and outs of it, which brings me to the condensation Q`s, all you need is ventilation, i supply so many households who use the heaters in there cony`s without any problems, except the ones that dont have enough venitlation.

still gets me why all the insulation but no need to use it, or much of it. If they are so cold anyway and loose loads of heat.......

It would be even worse if you didn’t bother; in terms of thermal efficiency, it just makes the most of the bad job that cons. are.

Anyway, on insulation, i have popped into wicks today and found some 30mm slabs, not the rockwool type but a more solid type which i can fit with plaster board with a VP barrier to the wall by screwing it direct to the wall.

Not a good idea to screw directly to the wall; you’d be better off using something like this; http://www.british-gypsum.com/produ...es/gyproc_thermal/gyproc_thermaline_plus.aspx
Unless it’s done correctly, you could have problems with all sorts of unhealthy & disgusting fungi growing behind there before too long, do yourself a favor & have a search/read back through the archive posts on the Plastering Forum where you will find many archive posts relevant to what you’re doing. Any of the regulars on there or in Building will respond if you come back with specific questions.

I will have a look kida, thanks for all the help

 

[ollysfollys]

The link you gave is the board i was looking at that i dont know the name of, i was told that i can screw them straight the wall or dot and dab them, that by a insulation supplyer?

So why wouldnt the slabs i found at wicks not work when used with plasterboard in the same way?

You say to ask with a specific question, you do and get so many different replys and do`s and donts, the one reason i am gettin glost with what to do.
I guess thats one problem with these forums.

 

[ajrobb]

Conservatories are not classed as living space, which is why you can build them without planning permission.

Unfortunately that’s not true; see the link above.

I don't understand:
They don't need planning permission because they are "permitted development"

They are permitted to leak heat like a sieve, unlike living space.

OK - so I was wrong to link the two.

 

[Richard C]

The link you gave is the board i was looking at that i dont know the name of, i was told that i can screw them straight the wall or dot and dab them, that by a insulation supplyer?

Don’t take any notice of suppliers, they generally only have half a clue & all they want to do is sell you stuff; you have to follow the manufacturers guidance & installation instructions. You can’t just screw the boards straight onto the wall; you need to prime the back with drywall adhesive & then dot & dab them followed by an additional mechanical fixing or they could fall off the wall in time; either nail plugs or screws.

So why wouldnt the slabs i found at wicks not work when used with plasterboard in the same way?

I’ve no idea what the insulation slabs are that you’ve found in Wickes but, in all probability, your not comparing like with like as far as thermal efficiency goes; a bit like comparing Celotex with polystyrene!

You say to ask with a specific question, you do and get so many different replys and do`s and donts, the one reason i am gettin glost with what to do.
I guess thats one problem with these forums.

You must always do your own research in good time before you start & then sift out the good advice from the bad. One of the big problems with forums is that so many of the posters are not trades or professionals but DIY pretenders who sometimes have a limited scope of knowledge. This Forum is better than most in that it does have quiet a few true trades & professional contributors, you just have to spot who they are.

With materials you should also remember you only get what you pay for &, very often, they may look the same but are not in reality.

 

[Richard C]

I don't understand:
They don't need planning permission because they are "permitted development"

Cons are only permitted development if they comply with the guidelines stated in the link & you have not used up any of your PDR on previous extensions.

They are permitted to leak heat like a sieve, unlike living space.
OK - so I was wrong to link the two.

Planning has little to do with Building Regs. A cons may need planning but doesn’t need Building Regs, PROVIDING it complies with the BR guidelines in the same link (listed lower down) that keep it exempt from Building Regs.

It can be confusing I know.