How do I plasterboard and insulate my conservatory roof..?

[RJD223]

Jonboy_t said:

Sorry bud, probably not describing it well, I meant the plastic roofing sheets that are already there - the actual conservatory roof itself. The bars that already support it (the metal bars), did you do anything with them to seal them first? With mine, I could push the plastic roofing and it would move within it's existing supports a little, I was just worried that this movement would let moisture in or allow movement behind the insulation that might lead to cracking.

Ah! No I didn't do anything to them - they'd never moved since it was installed so didn't see any need to.

They normally move, on another conny I had, because the end cap came off or that they hadn't been installed properly in the first place.

Maybe take the end caps off and put some kind of fixing through the aluminium frame which stops them sliding down (like a block of some sort)...

[gizlaroc]

Yeah, hate to say this as you have now done it, but Celotex is not the answer, you need to create an air tight barrier between the polycarbonate roof and the plastboard, otherwise it will get damp and just fall off.

Foil as done above is the best way.

Staple it on, then seal it properly with foil tape, batten over the foil and then plasterboard.

Also, I would make sure the poly sheeting is at least 4 cell and that you never get any condensation on the inside, if you do then replace that first with newer/better stuff.

[mondeoman]

RJD223 said:

I did this with mine... Was advised not to use the Cellortex insulation as there wasn't enough of a vapour barrier?...

Anyhow - it's ace - glad I did it - we now use the room all year round!

The insulation was from http://source4me.co.uk/store/insulation/multi-foil... (Foil Insulation SF19)

How did you create a vapour seal if the foil is just tucked behind the lowest batten?

[Royce44]

Sorry if I'm being thick. My missus has decided she would like this done. The battoning and boarding I'm fine with but I'm still struggling to get my head around the insulation method. So the foil above is stapled to the existing metal roof supports then it's needs to be sealed with foil tape all round so that no "room air" pentrates the ceilings void. Is that correct?

[227bhp]

I'd be quite worried about the extra loading on the roof.

[Spudler]

227bhp said:

I'd be quite worried about the extra loading on the roof.

That's was my initial thought.


Foil backed plasterboard if anyone's thinking of doing the same.

[227bhp]

Spudler said:

227bhp said:

I'd be quite worried about the extra loading on the roof.

That's was my initial thought.

Particularly as the one in the pic has no cross brace holding the side frames in.

[lothianJim]

227bhp said:

I'd be quite worried about the extra loading on the roof.

Can we get an update OP / RJD223?

Any issues?

[jon-]

Every issue. The celotex didn't stay in place, I couldn't mount the plasterboard, and even if it had gone to plan i would have still been freezing in winter and boiling in summer. Basically I fked up and gave up.

It's now my covid gym.

Also, wow, thread bump from the past.

[gizlaroc]

Well, I am 6 years in with mine.

Superfoil SF60 stapled to existing joists, taped up, battened out, 9.5mm plasterboard, skimmed and painted,

Still the best insulated room in the house. 7m x 7m with pretty high ceilings and we only use a 3kw electric rad that costs around £30 a month in the depth of winter, but we do use that room most.
Gas bill is down by around £30 a month all year, so cheaper overall.

[lothianJim]

jon- said:

Every issue. The celotex didn't stay in place, I couldn't mount the plasterboard, and even if it had gone to plan i would have still been freezing in winter and boiling in summer. Basically I fked up and gave up.

It's now my covid gym.

Also, wow, thread bump from the past.

I wanted to wait a while for better feedback.

I've just done similar, but with very lightweight materials. two layers of thermofoil separated by single batten screwed into the aluminium and covered with 3mm hardboard. I would guess about 50kg all together. It's worked well so far and is about 5 degrees warmer, so wondering about adding another layer with perhaps something a little weightier this time...but have no idea how to calculate the load the roof can support, and also whether i'm getting diminishing returns vs the windows by adding more insulation.

Encouraging to see at least one roof is still holding up though.

[gizlaroc]

What thermofoil?

I used YBS Superquilt.

I used one layer with 9mm plasterboard, made sure it was sealed with a gap between the quilt and glass, important, and it simply doesn't lose heat.

I have had snow on that roof a few times now and it just doesn't melt, that shows how good it is.

[lothianJim]

gizlaroc said:

What thermofoil?

I used YBS Superquilt.

I used one layer with 9mm plasterboard, made sure it was sealed with a gap between the quilt and glass, important, and it simply doesn't lose heat.

I have had snow on that roof a few times now and it just doesn't melt, that shows how good it is.

Ah, sorry, Thermowrap, not thermofoil. Basically shiny bubblewrap. Though it has made a fair difference, at a fraction of the weight. If i was going to do it again I would add more bulk, as I wasn't expecting the frame to be so sturdy and easy to work with.

[Equus]

Spudler said:

227bhp said:

I'd be quite worried about the extra loading on the roof.

That's was my initial thought.

Foil backed plasterboard if anyone's thinking of doing the same.

Bit of a late reply on this one, I appreciate, but it's worth mentioning that this sort of work technically brings your conservatory within the scope of Building Regulations control (because it no longer meets the definition of a 'conservatory' as having 75% glazed roof area), and Building Control will want to see a system that has an Agrement Certifiicate or other appropriate technical certification.

On another thread not far from here, someone had quite correctly calculated the additional weight of adding a plasterboard ceiling to a garage at about half a tonne, so the effect can be appreciable.

[98elise]

Equus said:

Spudler said:

227bhp said:

I'd be quite worried about the extra loading on the roof.

That's was my initial thought.

Foil backed plasterboard if anyone's thinking of doing the same.

Bit of a late reply on this one, I appreciate, but it's worth mentioning that this sort of work technically brings your conservatory within the scope of Building Regulations control (because it no longer meets the definition of a 'conservatory' as having 75% glazed roof area), and Building Control will want to see a system that has an Agrement Certifiicate or other appropriate technical certification.

On another thread not far from here, someone had quite correctly calculated the additional weight of adding a plasterboard ceiling to a garage at about half a tonne, so the effect can be appreciable.

I've always thought this would be the case, but if the original glazing stayed in place would that technically still be a conservatory?

I've seen adverts for proper roof conversions which are interesting, but I suspect done with no planning permission.

[Equus]

98elise said:

... if the original glazing stayed in place would that technically still be a conservatory?

No

The definition set out in LABC guidance is that 75% of the roof area must be formed from translucent materials. Plasterboard is not translucent.

98elise said:

I've seen adverts for proper roof conversions which are interesting, but I suspect done with no planning permission.

Repeat one hundred times (or until it sinks in): 'Planning and Building Regulations are different things'

Planning draws no distinction between a conservatory and any other form of extension. It is Building Regulations that treats them differently.

The 'proper roof conversions' are usually Agrement certificated and, if done by reputable companies, will be subject to Building Regulations.

The LABC publishes specific guidance, which can be found HERE

[Silverage]

I had my conservatory roof converted earlier this year (in lieu of a summer holiday, thanks COVID).

It was done by a local firm and while planning permission was not an issue, there was £275 in the cost for it to be signed off by their building regs guy for the reasons Equus mentions above. I reckon he was here no more than 10 mins and must have x-ray vision, but I have a piece of A4 paper for my money, so all is good.

[98elise]

Equus said:

98elise said:

... if the original glazing stayed in place would that technically still be a conservatory?

No

The definition set out in LABC guidance is that 75% of the roof area must be formed from translucent materials. Plasterboard is not translucent.

98elise said:

I've seen adverts for proper roof conversions which are interesting, but I suspect done with no planning permission.

Repeat one hundred times (or until it sinks in): 'Planning and Building Regulations are different things'

Planning draws no distinction between a conservatory and any other form of extension. It is Building Regulations that treats them differently.

The 'proper roof conversions' are usually Agrement certificated and, if done by reputable companies, will be subject to Building Regulations.

The LABC publishes specific guidance, which can be found HERE

No need to be patronising. I understand the difference between planning and building requlations (we've extended our house twice) however I wrongly assumed that a conservatory may be treated differently as some outbuildings are (unless I've got that wrong)

I'm sure there was a time when you didn't know the ins and outs of planning.

Edited to add....Thank you for the link. It's good to know there is a way of legitimately changing a conservatory to a more usable space.

Edited by 98elise on Tuesday 3rd November 17:51

[Equus]

98elise said:

No need to be patronising.

Apologies. It just gets very frustrating repeating this same stuff time after time.

To be fair, it is nuts that we've got no consistency whatsoever between what is exempt from Building Regulations and what is exempt from Planning: it wouldn't be too difficult to bring the exemptions into line with each other and/or to better integrate the two systems, but there is no political will to do so.

98elise said:

I wrongly assumed that a conservatory may be treated differently as some outbuildings are (unless I've got that wrong)

Nope, as far as Planning is concerned, all outbuildings are treated the same, too.

Outbuildings are outbuildings (no matter what they're built from), extensions are extensions (and a conservatory is just another form of extension).

The only 'special' types of domestic extensions in terms of Permitted development (Planning) are porches and roof extensions (ie. dormers), which have their own 'classes' under the General Permitted Development Order.

[Neo4403]

Hello, I am new to this diy forum but not new to piston heads :-).
I have been researching quite a lot on the same issue I have with the conservatory as posted by OP. After a lot of research I also did exactly the same installing 30mm PIR insulation (with 30mm gap to the polycarbonate roof) but after reading above comments I think I may have done the damage already especially that the PIR insulation is not plastered or installed upvc cladding. Some research showed that the PIR insulation should not be left uncovered as it causes respiratory issues.
The insulation is flushed to the frame. The conservatory has polycarbonate roof with glass on 4 sides, the 4th side being the connection to my living room which is a sliding door. Flooring is tiles but lower than the flooring level of the house. I can see air bricks so I guess there is no insulation under the floor. We planned to have an oil heater here to warm the room up and use it daily for dining or sitting. Room size is 3.5 x 3m.
My questions are:
1. Should I install battens to the ceiling and side frames and install plasterboard? Or is upvc cladding better?
2. Will the ceiling withhold the weight of battens and plasterboard or upvc cladding.
3. Do I need building regs check and certify this after above changes?
4. Is the insulation I added enough or do I need more?
5. Should I have the 2nd side also insulated and plastered as now it’s only the roof and one of the sides are done.
6. Should I insulate the flooring also by raising it and adding PIR insulation with osb boarding and fit laminate flooring or whichever.
7. How much would it roughly cost for all the above excluding the flooring and also for the flooring? Insulation coated approximately £150 for roof and one side.

Sorry for too many questions, thanks in advance folks for helping. I may consult a tradesmen to do this work as I am not an expert and especially don’t want to mess this up. I live in Bucks so any recommendations are also appreciated. I will try to post photos soon. Thanks

Edited by Neo4403 on Friday 27th November 17:47

Edited by Neo4403 on Friday 27th November 17:48

Edited by Neo4403 on Friday 27th November 17:50

Edited by Neo4403 on Friday 27th November 17:51

Edited by Neo4403 on Friday 27th November 17:53