help with insulation in sloping roof

[Deano3]

Hi everyone I have ripped out some large fitted wardrobes from kids room as the cupboard was as large as the room and you couldn't even for his bed in the room without it blocking cupboards or the door, it's on the only part of the house with roof that slopes from the peak of roof down to the 1st floor, there is a large price of wood across middle of room I take it holding the roof up but I have a few questions , I am on mobile and I have uploaded pics of the room from the door and I can see the tounge and groove wood across the sloped roof I have removed that and uploaded images of the mdf or chipboard that is covering roof, I removed that and you can see rafters woth a small amount of insulation in there it's a very cold room and what you think is best option buy the insulation that can be cut and pushed into rafters then do I need the silver sheeting then plasterboard ? Or leave what is already on and fit the plasterboard that has insulation on already then pay someone to plaster the roof ?

Any opinions welcome or help appreciated , I want to build a false wall with some cupboards in after insulation sorted

Like the picture provided

Also the floor was all good but were the large cupboard was the floor is only mdf or chipboard and very weak it's about 15mm thick or so will I need small boards or can u but large floor boards that are strong etc

Thanks dean

 

[foxhole]

You could board over the cold section with insulated plasterboard, example below, price increases with the thickness.
http://www.buildingmaterials.co.uk/...&network=pla&gclid=CNyF1LyKscgCFYMewwodPyINyQ

 

[Deano3]

Thanks for the reply, would you just leave the mdf and everything on the celing then just add the plasterboard/insulation straight onto that ? Thats the cheapest price i have seen that i was looking at b and q etc , is that site often the cheapest ? Actually just looked and deliver is fortune

so you think that is better option than removing all the wood amd totally repacking the rafters ? Not sure if would have been cheaper etc what you think ? Also wasnt sure if to remove the roof on other half of room but already plastered and painted etc so would make a huge mess so might just do the lower half of celing as planned


also what you think about floor would you remove all the mdf or chipboard or whatever it is ( you can see the normal floot boards yhen were cupboard was they change and are very weak) whats best floor boards that wont bend or anything ? Do i just remove whats down and screw new ones directly onto the joists

thanks again dean

 

[foxhole]

Local builders merchants are often cheaper than the 'sheds' , floor could be replaced with a sheet of ply .

 

[Deano3]

Hi everyone sorry to open an old thread back up just have a few questions, I have took up all the floor and fitted sheets of plywood I am now going to tackle the room, I am going to remove the mdf Off the sloping roof but have a couple of questions, after I remove the mdf and the insulation from the rafters i can see the felt stuff when I get to this stage

1. What is the best thickness solid insulation to fit into the roof ?

2. Is there a specific gap I need to leave from the felt to insulation and from insulation to plasterboard?

3. Lastly I was going to put plasterboard with the silver sheeting on the bottom is this correct ? So felt on the roof then the solid insulation then silver sheet with plasterboard ?

Also should I put tape over the joins of the plasterboard ?

Sorry for all the questions everyone just cracking on with it now and not sure on these few things, also when I make the stud wall should I add insulation in there then just plasterboard the front

Any help would be greatly appreciated
Thanks dean

 

[foxhole]

As thick as you have room for, 100mm would be good then foil tape the joins and add insulated plasterboard for a an effective job.

My loft

• foxhole
• 3 Dec 2015
• 1

100mm insulation .

 

[Deano3]

Thanks for that mat that's very helpful ,do I push the solid insulation into the rafter gaps ? If so I won't need the foil tape as there will be insulation in the rafters then rafter then insulation in next one and so on, I was going to the plaster board (using the plasterboard with a silver sheet on the back onto the wood rafters ?

Do I need to leave gap from the felt under the roof tiles ,think must be the membrane above the current insulation ? And do I need to add tape in beetween the plaster boards ?

Also when I make my stud wall on the sloping roof would you put insulation I beetween the wood then plasterboard over the top ?

Thanks again and help is great
Dean

 

[Deano3]

Hi here is a pic to help out

I am removing the mdf some one out there on the sloping ceiling and found not much insulation behind it, when I take that insulation out and put solid insulation in pf 100mm thick, (the rafters from bottom to top are 15cm) do I just cut to size then push up into the rafter right to the top or stop before hits the very top ? And then do I just put plasterboard with the silver sheeting across the rafters to seal in?

Really need help as want to get this finished so any help greatly appreciated
Thanks Dean

 

[foxhole]

Leave the insulation flush with rafters.

 

[Deano3]

Leave the insulation flush with rafters.

Thanks for that so remove the existing insulation and push solid insulation in till its flush so that would leave 5cm or so at the top for air to flow?

And as for plaster board would would you then just plasterboard directly onto the rafters with the plasterboard with the silver sheeting on one side ?

Do you just use wood screws and will I need to tape the joints ?

Thanks again as you have been great help
Dean

 

[foxhole]

Use plasterboard screws and tape all joints.

 

[Deano3]

Use plasterboard screws and tape all joints.

Thanks for that will go get insulation later would you use plasterboard with the silver sheeting on one side and gave that up and screw directly onto the rafters ?

Removed insulation this morning, dirty job

Found a few little neat things but nothing alive and moving so hopefully be fine you think they are nothing ?

And would you do what I said with plasterboard

Thanks again foxhole for your help

 

[foxhole]

I would use thermal plasterboard, foil back is ok though.

 

[DavidSWP]

Ignore most of these replies. Do your Science and maths and put the best insulating material into the roof that it can possibly accommodate while still not infringing on the room space - check out U-Values etc. Synthetic materials can offer the best insulation but are bad for the environment in their production. Having said that I used Cellotex on my sloping room because I am a selfish git.