wall insulation

[fred]

I wish to fix 100mm insulation board to the outside of a block wall and then fix t.g and v boards outside that again

Obvious way would be to fix a framework of 100 x 50 softwood to the block wall and set insulation boards inside this and then fix t.g and v to the 100 x 50 framework, but what would be the best way to fix the 100 x 50s to the block wall ?

Would it be in any way be feasible to glue the 100mm insulation boards to the block wall and then fix the t.g.and v. to the insulation panels thus elimination the 100 x 50 framework ?

I'm way oiut of my depth here.

[harry]

Frame fixings. You can get them up to 150mm long. They are intended for window and door frames. Counterbore as necessary.

Use feather edge or shiplap boarding. Feather edge is cheap and comes pre-treated. Easier to cut and fix. The insulation needs to be totally sealed, No airleaks between it and the wall or your work is all wasted. This is your biggest problem.

[The Natural Philosopher]

Big Fuckoff Hilti gun?

Nit sure your building inspector would like that

[Tim Lamb]

Wot I did (agricultural barn) so needs BC approval for house.

Use *distance screws* to secure battens over your insulation.

Hammer drill through batten and insulation into wall. Fit plastic plug to screw and tap through hole until seated in the wall. Tighten screw until head is seated in the batten. Batten position can now be adjusted by further tightening or loosening the screw.

I wouldn't use cheap feather edge for your house. It comes with lots of knots which can drop out as the timber dries.

[Brian Gaff]

Is this kind of insulation really of any use? Here in single non cavity wall land, I'm not sure there is an economic way to insulate walls. Brian

[John Rumm]

What I plan to do here, is fix insulation boards first - just using a couple of hammer in insulation fixing fasteners[1] to hold it up. Then fit the battens on top of the insulation, these will use long screws through the insulation and into the wall drilled and plugged. Then screw/nail the cladding to the battens. I can't see much point in fixing the battens directly to the wall, since you make the job of insulating harder, and introduce cold bridges.

[1] e.g.

or

[Brian Gaff]

Yes to their credit this was exactly what one company touting for work said when I rang them, the advice was either move or forget it. Brian

[RJH]

Won't you have cold bridging (such as it is) anyway - through the long screws fixing the insulation?

[John Rumm]

The insulation fixings are usually nylon. Its the wood fixing that would need proper screws. Yup you would get some on those, but I can't see it being much (and certainly less than ficing timber to the wall and insulating around it).

[fred]

A very interesting discussion. Has given me much food for thought. Thanks to all for their input

[John Rumm]

Probably worth noting that much depends on how you plan to cover your insulation. If using a light weight render option, then you probably wont need much in the way of battening (although a mesh finished insulation board would probably bee good).

Personally I was leaning that way since I wanted to overboard the insulation (feather edge or similar).

[DICEGEORGE]

External insulation is better than internal, because you can get a complete envelope around the house (the bricks of which become a heat store and smo oth out the difference between day and night). Whereas with internal there is often a huge gap at the 6 inches of wall under the upstairs floor, which in my house has holes where the rafters go and so is even less insulated t han most of the wall. plus you dont have to move all the furniture and rede corate.

But external insulation doesnt work if it gets wet.

My house has Stone outside so I cant cover it and am spending ages pulling up the floorboards by the outside walls and firefoaming kingspan into the g aps. But it feels a lot warmer.

Another heat loss was where the ceiling met the walls under the eaves, ther e was just a thin layer of plaster.

George

[harry]

This is true. You have to go down & select your own without knots at the yard

[harry]

The big problem is round windows and doors. Also the amount of overhang on the roof.

My house was solid walls. I put another wall up in front of the insulation. I extended the roof. I was re-slating it anyway.