Insulation question

kitkat9933 · 1 Aug 2023 at 00:01

We had part of our garage converted into a playroom.

Unfortunately, we hired one proper cowboy and then one builder not fit for purpose, before having someone else finish the leftovers off.

A new stud wall was put up in the garage to split up the new room off on the back of the garage. This was plaster boarded on both sides and skimmed. In between a bit of what I think was rockwool was put in rather than cavity wall insulation (the outer cavity walls seem to have proper cavity wall insulation from the bits I could see at various stages, as the outer walls of the new room were uninstalled and just brick and breeze block with a cavity)

A dropped stud ceiling was addded to hide cables and pipework in what was the original garage ceiling. Rockwool again I think was added here.

Now the walls are all boarded up and I can’t see anything but the dropped ceiling with the insulation there now.

The problem lies in the new room, where two
cable cutouts have been added to hide hdmi cables in the wall, I am getting a large draft that will not massive, does impact the temp a little.

So I had some questions as scared of cowboys again:

1. Is rockwool suitable for the new dividing wall insulation and suspended ceiling. Heard some people say it could get mould and SAML etc. others said as it’s in the garage with other layers, it shouldn’t be an issue.
2. Would using wood board at the front of the suspended ceiling help with my draft issue? As I’m guessing it’s going through there and down the gaps in the wall then through the hdmi holes. Thinking of wooden board screwed on to the frame so it could be taken out to get in there if needed etc.

Any help appreciated !

(Please also forgive any grammar/spelling issues due to late night posting )

Pictures for reference https://imgur.com/a/0tIx8rU

Matt-Page · 2 Aug 2023 at 00:30

Hey - Rockwool is "OK" but it doesn't meet building regs from what my research showed. It's not the best insulator but will do a job.
There's quite a bit to comment on here, but I'd need to see some more details of the walls construction... Do you have any more in-progress pictures during the building work?

I did similar to what you have had built myself (I'm sat in it now). I did a build thread on it which you may find useful: https://forums.overclockers.co.uk/threads/project-garage-office-workshop-thread.18932259/

G_Wizz · 2 Aug 2023 at 01:07

Rockwool "wicks" moisture so shouldn't be used for external walls, should be ok for dividing walls as long as the external walls have been done properly and the humidity isn't too high. It's ok for ceiling as long as their is an air gap above, if it's solid will hold moisture and eventually you might get damp staining.

kitkat9933 · 2 Aug 2023 at 06:07

Matt-Page said:
Hey - Rockwool is "OK" but it doesn't meet building regs from what my research showed. It's not the best insulator but will do a job.
There's quite a bit to comment on here, but I'd need to see some more details of the walls construction... Do you have any more in-progress pictures during the building work?

I did similar to what you have had built myself (I'm sat in it now). I did a build thread on it which you may find useful: https://forums.overclockers.co.uk/threads/project-garage-office-workshop-thread.18932259/

Not really any during construction as I was in hospital with our newborn.

I did see your build and looks a lot better than the “pros” that did mine.

kitkat9933 · 2 Aug 2023 at 06:11

G_Wizz said:
Rockwool "wicks" moisture so shouldn't be used for external walls, should be ok for dividing walls as long as the external walls have been done properly and the humidity isn't too high. It's ok for ceiling as long as there is an air gap above, if it's solid will hold moisture and eventually you might get damp staining.

That’s helpful thanks. So ceiling seems okay.
It’s the dividing wall that may be issue as the garage door does let a breeze in and the external walls that side are non insulated.

Sounds like it may be a problem from the sounds of it.

Lean · 2 Aug 2023 at 09:56

A few thoughts while I wait for the rain to ease. Could you insulate the inspection panels as a quick fix to their draughts?
If you dont feel there is enough insulation in I suppose you could overboard with some thermal insulated plasterboard then skim.
Often laminate flooring is used in these projects which gets cold from draughts under skirtings or doors. You could caulk the skirting with a flexible silicone which will still let the laminate move. It looks like you basically have a cold roof system in your new room. I didnt see any vapour barrier in your pictures. The draught from the garage door may not be a bad thing. Is it a garage with a flat roof? Blocking the dropped ceiling with no ventilation or vapour barrier (warm side) could lead to problems.

kitkat9933 · 2 Aug 2023 at 11:12

Lean said:
A few thoughts while I wait for the rain to ease. Could you insulate the inspection panels as a quick fix to their draughts?
If you dont feel there is enough insulation in I suppose you could overboard with some thermal insulated plasterboard then skim.
Often laminate flooring is used in these projects which gets cold from draughts under skirtings or doors. You could caulk the skirting with a flexible silicone which will still let the laminate move. It looks like you basically have a cold roof system in your new room. I didnt see any vapour barrier in your pictures. The draught from the garage door may not be a bad thing. Is it a garage with a flat roof? Blocking the dropped ceiling with no ventilation or vapour barrier (warm side) could lead to problems.

I have insulated the panel but I think it’s air getting in through the dropped ceiling in between the insulation and plasterboard that’s coming out in the room.

The floor is fine as they have used thick underfloor insulation boards, wooden board then it’s been skreed flat with LVT on top.

The garage is a slanted roof connecting to the main house with its own ceiling and rafters above the dropped ceilings.

It’s more how to stop it getting into the room and blocking the draught from the garage door was my first thought with a board to the ceiling.

If I added the board to block most of the airflow but added some ventilation would that work? Or any other way to solve it?

Matt-Page · 2 Aug 2023 at 11:51

Can you post some more pictures of the room and the view from the garage side and indicate which wall is which?

flea.rider · 2 Aug 2023 at 12:00

there's not much in that wall is there ? i would have used thermal insulation board cut to size then foam if it needed it round fittings ..

kitkat9933 · 2 Aug 2023 at 12:48

Matt-Page said:
Can you post some more pictures of the room and the view from the garage side and indicate which wall is which?

Added some further pictures here.

The tv recess in the room is backing into the access panel on the new wall within the garage.

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flea.rider · 2 Aug 2023 at 13:27

have a climb up and see if those rolls of insulation go all the way back .. my guess is no .. it's been finished really well on the inside shame you might have to pull some of it out

kitkat9933 · 2 Aug 2023 at 13:40

flea.rider said:
have a climb up and see if those rolls of insulation go all the way back .. my guess is no .. it's been finished really well on the inside shame you might have to pull some of it out

They go all the way back over the ceiling with a big air gap over the top. Only the front is piled high a little bit with no real gap but not sure if that’s the sprinkler company that did that when playing around with the sprinkler.

Mercenary Keyboard Warrior · 2 Aug 2023 at 15:03

If your suspecting draft from garage door, wait for a windyish day. get one of them smoke bombs they use for chimney flue testing, light it inside the garage door area and then go into your room, you should be able to see some smoke seeping in if its coming in via drafts from that area

flea.rider · 2 Aug 2023 at 15:32

kitkat9933 said:
They go all the way back over the ceiling with a big air gap over the top. Only the front is piled high a little bit with no real gap but not sure if that’s the sprinkler company that did that when playing around with the sprinkler.

now the way i see it is you have a lot of heat escaping .. whole lot should have been thermal insulation board 60-80mm thick in the walls and prob 110-130 on the ceiling or at least compacted rockwool all he's used is cheap loft roll by the looks of it .. but i'm not a builder i just do my own house

kitkat9933 · 2 Aug 2023 at 17:00

flea.rider said:
now the way i see it is you have a lot of heat escaping .. whole lot should have been thermal insulation board 60-80mm thick in the walls and prob 110-130 on the ceiling or at least compacted rockwool all he's used is cheap loft roll by the looks of it .. but i'm not a builder i just do my own house

Trying to understand how to save this without ripping the whole thing out and losing too much more money.

kitkat9933 · 2 Aug 2023 at 17:17

One thing I would say it’s holding heat relatively well, I think if this small draught could be removed, it would be a lot better.

I know the 2 external walls and the one shared with the house have decent insulation, so it’s really this new dividing wall and the ceiling.

Matt-Page · 2 Aug 2023 at 17:40

kitkat9933 said:
Added some further pictures here.

The tv recess in the room is backing into the access panel on the new wall within the garage.

imgur.com

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From those pictures, I'd say your builders have given you a decent finish, however PIR insulation and a vapour barrier(plastic sheet) would have been my preference.

Can you elaborate on where you can feel a draught?

My garage room has 0 wind/draughts coming in, and my access door is on the garage side.
Your access door appears to be on the side?;

I assume that white door in the garage side wall is for you to be able to access cabling?

kitkat9933 · 2 Aug 2023 at 18:00

Matt-Page said:
From those pictures, I'd say your builders have given you a decent finish, however PIR insulation and a vapour barrier(plastic sheet) would have been my preference.

Can you elaborate on where you can feel a draught?

My garage room has 0 wind/draughts coming in, and my access door is on the garage side.
Your access door appears to be on the side?;

I assume that white door in the garage side wall is for you to be able to access cabling?

That is correct, the wholes for the tv cabling are where the main draught are coming through. In addition to around the sprinkler head (waiting for sprinkler cap still)

Matt-Page · 2 Aug 2023 at 18:07

kitkat9933 said:
That is correct, the wholes for the tv cabling are where the main draught are coming through. In addition to around the sprinkler head (waiting for sprinkler cap still)

Ok. Makes sense.
On the garage side of the wall I can see insulation. Does the wall ok the garage side meet the ceiling and is that sealed from the garage side?

If it is, then your issue is that white door/box and it's where the wind is going. I would investigate sealing that door better. Particularly around the edit of the frame that's up against the wall and the door itself. You could put something over it that seals it to prove it.

Realistically how often are you going to need to open that door once everything is fitted? Not often I would assume...?

kitkat9933 · 2 Aug 2023 at 18:10

Matt-Page said:
Ok. Makes sense.
On the garage side of the wall I can see insulation. Does the wall ok the garage side meet the ceiling and is that sealed from the garage side?

If it is, then your issue is that white door/box and it's where the wind is going. I would investigate sealing that door better. Particularly around the edit of the frame that's up against the wall and the door itself. You could put something over it that seals it to prove it.

Realistically how often are you going to need to open that door once everything is fitted? Not often I would assume...?

The wall does not go to the ceiling, there is a lowered ceiling to hide pipework etc that was in the garage originally and level it up with the main house.

I was thinking of boarding up from the wall to the original garage ceiling to stop anything coming from above (assume some trickle vent or something needed?

Just sealed the access panel with some bags and tape and didn’t make a difference, not sure if that’s enough to test.

Insulation question

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