How to fix this insulation mistake?

Mat the trasher

Hi,



I'm looking for the best way to fix this insulation mistake made by the builder.





I have a single story side of the house with three rooms along its lenght, the rooms on either end have vaulted ceilings but the middle room has a normal height ceiling. I couldn't understand why this room was always cold, checked rad, which was working, then blamed the rad over.
anyway with time on my hands I climbed into attic space and found that the pitched rafters were insulated not the ceiling, and there was a vent gap open at on the outside wall so there is plenty of air circulating in this space.



How do I fix this properly, seal the vent? with what? or insulate the ceiling, ( if insulate the ceiling the side walls need to be done also no? )



cheers!

Yellow_Fern

Its tricky. It is like in between a warm attic and cold attic. if the holes are on the windward side you will get horrendous windwashing. Take more photos of the hole from the otherside. Even if you seal the hole there may be other problems like attic condensation. Installing a membrane on the vaulted insulation might be best but could be very finicky job. People in construction forum might know.

mickdw

How is roof ventilation handled in vaulted section?
If it is insulated on slope with roof ventilation over, you could do the same detail straight through the house meaning the lower ceiling in middle room would be just an artificial lowering with fully insulated space over it for storage or whatever.
As bit stands, your insulation is wasted.

GreeBo

Easiest solution might be to just overboard your ceiling with insulated plasterboard.

Yellow_Fern

GreeBo wrote: »

Easiest solution might be to just overboard your ceiling with insulated plasterboard.

But means means everywire and every vent is sealed where it meets the plasterboard.

Calahonda52

GreeBo wrote: »

Easiest solution might be to just overboard your ceiling with insulated plasterboard.

can you clarify exactly where you mean to go overboard ?

GreeBo

Calahonda52 wrote: »

can you clarify exactly where you mean to go overboard ?

Basically you are putting a layer of insulated plasterboard on your ceiling over the existing ceiling, but you are doing it from the room side rather then the attic side.
You will need to redo any coving and also get it skimmed and painted again though. Shouldn't need to do the walls.

What sort of access do you have to the attic above the ceiling?
If it's all exposed then you can just insulate as you would an attic. Though I'd be careful, if the rooms either side are vaulted your ceiling may not be structural and just there to hold the plasterboard, you don't want to fall through!

GreeBo

Yellow_Fern wrote: »

But means means everywire and every vent is sealed where it meets the plasterboard.

I don't follow what you are saying here?
I'm suggesting insulated slabs on the room side.

Yellow_Fern

GreeBo wrote: »

I don't follow what you are saying here?
I'm suggesting insulated slabs on the room side.

Yeah, I am no expert at all but I think youd want to carefully seal up any perforations in the ceiling, before or after doing works. My point was if you use a membrane youd have a different strategy.

Mat the trasher

Thanks all for your relpies,


I was concered that a fix should not be just the simple one, it would be easy to put insulation down on the ceiling, but there would be water pipes left above pertaps a frost risk and would bury the forced vent unit. also the two side walls to the vaults in the adjoining rooms would also need additional insulation.



I was thinking to vapour barrier under the roof insulation, ( under the roof pitch and seal it to the outer edge of the ceiling, this would leave ventilation on felt and insulation but not into the attic cavity?


Thought there might be an specialist on here that might say what would normaly done in this situation, reckon it was just an over sight by the builder.

Yellow_Fern

Mat the trasher wrote: »

Thanks all for your relpies,


I was concered that a fix should not be just the simple one, it would be easy to put insulation down on the ceiling, but there would be water pipes left above pertaps a frost risk and would bury the forced vent unit. also the two side walls to the vaults in the adjoining rooms would also need additional insulation.



I was thinking to vapour barrier under the roof insulation, ( under the roof pitch and seal it to the outer edge of the ceiling, this would leave ventilation on felt and insulation but not into the attic cavity?


Thought there might be an specialist on here that might say what would normaly done in this situation, reckon it was just an over sight by the builder.

I am a total DIYer, more of the professional builders are on other sections of the forum but I suspect they would suggest that putting an airtightness membrane on rafters is a viable way, the question is have you got the access to do that? Of course you might have secondary gains from having more of the air unit and water inside the warm part of the house. Potentially you'd end up with better airtightness than even if the builders didnt make this mistake.

GreeBo

Mat the trasher wrote: »

Thanks all for your relpies,


I was concered that a fix should not be just the simple one, it would be easy to put insulation down on the ceiling, but there would be water pipes left above pertaps a frost risk and would bury the forced vent unit. also the two side walls to the vaults in the adjoining rooms would also need additional insulation.



I was thinking to vapour barrier under the roof insulation, ( under the roof pitch and seal it to the outer edge of the ceiling, this would leave ventilation on felt and insulation but not into the attic cavity?


Thought there might be an specialist on here that might say what would normaly done in this situation, reckon it was just an over sight by the builder.

Why would the side walls in the vaulted run need insulation? I thought you said they were warm?

Obviously you wouldn't block the forced air unit and the pipes should be insulated anyway

mickdw

Mat the trasher wrote: »

Thanks all for your relpies,


I was concered that a fix should not be just the simple one, it would be easy to put insulation down on the ceiling, but there would be water pipes left above pertaps a frost risk and would bury the forced vent unit. also the two side walls to the vaults in the adjoining rooms would also need additional insulation.



I was thinking to vapour barrier under the roof insulation, ( under the roof pitch and seal it to the outer edge of the ceiling, this would leave ventilation on felt and insulation but not into the attic cavity?


Thought there might be an specialist on here that might say what would normaly done in this situation, reckon it was just an over sight by the builder.

We need more detail. Is it a cold roof with ventilation at eaves running up under felt at the vaulted sections?