Adding weatherboard cladding to a house

Jeepers_Creepers

FreeBear said:

TheSaint_2 said: For insulation I have seen a simple silver foil from ybs and also ybs do something called super quilt as well. Alternatively I could use a more rigid board insulation like cellotex?

From what I have seen of these multi-layer foil insulation, they are pretty good at reflecting radiant heat, but are very poor at insulating against conducted heat - If you look at the recommended method of installation, the manufacturers (nearly) always specify using foils in conjunction with PUR type boards. One needs to ask why.... If it was such a wonderful material, why isn't everyone using it.

If you are going to insulate a wall, then by far the most effective method is to fix Celotex/Kingspan boards and then render or clad - Be aware that if you are doing more than 25% of the exterior walls, then Building Regulations apply. If you involve Building Control, they may well reject the use of multi-foil insulation and insist on "proper" insulation boards.

If you are going to clad, please don't use uPVC - It will look tired and tatty fairly quickly. Timber cladding will age nicely, and if you pick the right wood (Cedar), will last a long time. At the moment, timber prices are all over the place, so it might pay to wait for supply/demand issues to settle down.

Ah, have to say I just assumed that the cladding I keep seeing on new houses around her was PVC. It's clearly not wood.

Quite a variation in quality of finish too, from crude very-faux grain, to pretty realistic. You'll probably need to check samples, T'Saint, or stop and ask whenever you see cladding on a house that you like!

Jeepers_Creepers

I still don't 'get' external insulation. I just can't believe it's anywhere as effective as even a thin internal layer.

If a house has a cavity wall, this cavity will be open and ventilated. How the 'ell does putting a layer of insulation on the outside of the outer skin possibly have a measurable effect?

FreeBear

Jeepers_Creepers said: I still don't 'get' external insulation. I just can't believe it's anywhere as effective as even a thin internal layer.

If a house has a cavity wall, this cavity will be open and ventilated. How the 'ell does putting a layer of insulation on the outside of the outer skin possibly have a measurable effect?

Depending on when the property was constructed and what standard practices were at the time, there may well be a cavity closer at the top. Without a close look under the tiles, it will be next to impossible to say for certain.

In principle, I would generally agree that internal wall insulation offers some benefit if done right. The downside is the disruption and slight loss of floor space.

Section62

stuart45 said:

I prefer the look of tile hanging myself, but it matter of personal opinion. On top of the blocks are probably 2x2 counter battens, then 2x1 tile battens. There's not a lot of room for insulation, most people get the cavity insulated.

I've seen some cases where 50mm blocks were used on the outer leaf to help create the recess needed to accommodate the necessary timber.

In that situation I think a generous increase in insulation somehow is really important.

stuart45

50mm blocks are really tricky to lay. I've only ever done upper partition walls with them. Surprised they got away with them on the outer skin as leaves are surpossed to be a min of 90mm. 
Did an extension once with. 75mm blocks on the outer skin but as they had 15mm of tender that counted to the thickness back then in the 80's.

TheSaint_2

 I agree that adding insulation to the outside is not going to be anywhere near as good as doing it on the inside. I don't know if the cavity is closed or not at the top, but it is extremely drafty. I recently replaced the windows and had the cavity open when doing it. A real gale blowing through. And that is with the blown fibre glass in the cavity (useless!!). I don't have the option of insulating inside unfortunately. The wife just wont allow it 🤣

Maybe if I put something to reduce the draft on the vent bricks.. But then I expect I will get moisture build up.