Insulation of a solid brick wall

[Matt711]

Hi,

I have just moved I to a 1930s solid brick wall bungalow and I am looking insulate the walls. So far I have cO spidered two ways, and as you can probably tell I'm still a no ice at this!! But the more I read, the more I get confused!!!

I was originally looking to place batons at 400mm centres, then fill with 50mm celotek pir insulation board then cover with 12.5mm plasterboard. The insulation board is 450mm in width so I presume that I can just cut off the remaining 50mm to fit the gaps??? Or can I use 100mm cavity slab with a moister liner then The plasterboard.

Or.... Would you just dot and dab the insulation board straight to the wall, then bond the plasterboard to the board using adhesive and screws???

Sorry if this sounds silly, but want to get it right!!!

Matt

 

[PrenticeBoyofDerry]

Not silly at all and as you have pointed out in you thread, there is more than one method to insulate single skinned walls.
This may be a useful link
http://www.kingspaninsulation.co.uk...herm-K18-Insulated-Plasterboard/Overview.aspx

 

[^woody^]

If battening you would space battens to suit the insulation. not cut 50mm or so off it. In reality though, you would by big 8x4 sheets and cut it down to sizes which avoid waste

It will be difficult to bond plasterboard to insulation board on site. Either buy pre-bonded insulated plasterboard, or batten and dry-fix

 

[Matt711]

Hey,

Thanks for the replies and the link.

Think I will place the batons at the insulation length, as you say easier and creates less wastage!!

Spoke to my friend last night, he suggested the following:

25mm pir board stuck to wall using adhesive.
Baton at 450mm onto the pir insulation using screws into wall.
Then insulate between batons using either 50mm cavity board or 100mm cavity slab
Then plasterboard and plaster.

This overkill or correct??? If wrong I'm thinking just sticking to the above without the 25mm pir board and baton straight to the wall.

Matt

 

[Matt711]

That correct or overkill??? Looking to get this sorted ASAP as hoping to start work on the room Friday!!!!

Matt

 

[^woody^]

Your friends advice is sound

In general terms, ideally you would want as much insulation as possible, and a continuous layer to prevent any colder spots on the wall

Foil backed insulation is almost twice as efficient as quilt, but it costs more.

I would batten the wall first, insulate between them, and then put the continuous layer on the front before the plasterboard. This does away with the need to fix the sheets to the wall, and removes chances of air voids

 

[cegla]

You have to remember to use breathable plaster or blocks otherwise you can "cook" your wall,you can find some is ytong multipor block which allow moisture to escape.
I done my one room as experiment I use 2"x2" timber and made frame looks like hallow wall 50mm from house wall
,then between timber I put chicken wire ( it holds the wool to not touch wall) and isolating wool in slabs 2" thick.
Cover everything with plasterboards.
And last thing on the top and bottom of the wall you need vents where top one is bigger than bottom one to create draft and remove moisture.
Minus of that is you loose about 100mm of your room.
Room is much warmer.

Luk

 

[^woody^]

You dont vent a lined wall!

Also, the continuous layer of PIR board behind the plasterboard acts a a vapour check

 

[Matt711]

So if I have a vent in the wall already, do I board straight over this or do I have to allow for this In the plasterboard???

Also the only reason he suggested lining the wall with pir board then batonibg as it cheeper than insulated plasterboard????

 

[^woody^]

So if I have a vent in the wall already, do I board straight over this or do I have to allow for this In the plasterboard???

Also the only reason he suggested lining the wall with pir board then batonibg as it cheeper than insulated plasterboard????

If you have an existing air vent to the room from outside, then this should go through any dry lining.

What you don't do, is vent air into or through any cavity behind the dry lining.

Choice of insulation is down to cost, practicality and efficiency of any chosen insulation. PIR board (ie the foil backed types) are the most efficient for any given thickness.

 

[Matt711]

Ah got it, so I could baton around the vent, cut the insulation and plasterboard to encorperate the vent and add a new vent plate on the plasterboard, that ok????

Or is there a better way?

 

[theoldun]

Or is there a better way?

There are 4 ways to insulate an external one brick thick wall.
We will give you what we consider, not to be the cheapest solution but the best and the easiest way for a DIY.
First you must decide what U value you require. Present day U values are 0.28W/m2k and you should try to achieve this or better.
Dot and dab is not recommended on a solid wall and should only be used on a cavity wall.
Build a new stud wall against existing external wall with 50x75 CLS timber finished size 38x63.
Uprights at 600 centres, centre noggins out of same timber 1200 centre down from ceiling.
Fill voids with 50mm GA4000 Celotex and finish with 25mm PL4000 Celotex screwed perpendicular to the studs.
25mm PL4000 is 12.5mm of insulation bonded to 12.5mm of tapered plasterboard. This will give you your finish and will counter any cold bridging from studwork.
On a moderate exposure wall this will give you a Resistance value of 3.90m2K/W and a U value of 0.26Wm2/K.
Hope this helps
Regards oldun

 

[Mike555]

Hi Newbie to this excellent forum.

Looking to insulate the internal solid walls, ( Other side of wall is external walls ) on my very hard to heat, cold Edwardian solid 9" brick and 9.5 ft ceillings with no cavity house.

I've read and re-read the advice on this forum and others and just want to make sure I have not missed anything.

Questions
- Do I need to remove wallpaper first ?
- Why battons ? - What are the benefits ?
- How do i fix batons to maintain a damp course ?
- Can I not screw direct to existing walls ? ( Framing screws )
- Any disadvantage with this approach ?
- What CELOTEX product ? ( PL4000 or SW3000)
- Any thoughts on using FERMCELL rather than plasterboard - to accomdate rads and shelves / etc.
- Do i apply a seperate vapour layer barrier ? ( plastic sheet ? )
- Whats best system for a reasonable DIY'er, who is paranoid about damp
and preventing condendation !


Finally - Cheapest place to buy Celetox please.

Thank you in advance.

Mike.

 

[Mike555]

Anyone ?

 

[^woody^]

I'll do number 1. Yes