Wood fibre boards on internal walls

[Jblakes]

Evening all,

So I've boarded out all the external walls of both bedrooms, and now on to the internal walls, this is all internal wall insulation.

Anyway, should I board internal walls (as in the ones where both sides are inside the house) or walls that's a shared with neighbours? Hope they make sense?

Kind regards
James

 

[malcolm]

Internal walls between rooms of your own house don't make any sense to insulate. Neighbours wall even less as even if they are skinflints they are still likely to have temperatures within 5 degrees of you. It's the 20 degree difference to outside that pays for insulation.

 

[Jblakes]

I thought that was the case. So just external walls then

 

[Jblakes]

Do you put wood fibre boards on the ceiling? If so, I assume just the ceiling directly below the roof?

 

[Lacan07]

No need to insulate internal walls or party walls.

 

[Lacan07]

Do you put wood fibre boards on the ceiling? If so, I assume just the ceiling directly below the roof?

No, not on ceilings, if you want to insulate between floors use flexible insulation between the joists. Most people don't insulate between floors but obviously you'll need to insulate beneath your roof in which case you between the joists in the loft space.

 

[Jblakes]

Thank you for that, so hopefully last few questions.

We have a chimney breast in the bedroom that's I've boarded upto the ceiling and due to plaster. The issue is above the ceiling into the roof, I've left an airgap from chimney to insulation and I can feel the ceiling of bedroom is cold. Can I continue to board upto the top of the chimney with woodfibre, and then place insulation up next to it to get rid of the cold stop.

Also we have a sloped roof at the edge of the room, anyway to insulate this without blocking the eaves up?

Kind regards
James

 

[Zebra]

I'm not sure I understand your first paragraph, Jblakes, you've left an air gap vertically between the chimney, and the insulation that's on the walls above the ceiling? To what end?
Regarding your second point, are you insulating under or between the rafters? With woodfibre again? Is the ceiling still in place? I did mine by insulating between the rafters (the ceiling was removed), leaving a 25mm air gap between the top of the insulation and the bottom of the roofing felt. I then insulated under the rafters too, and boarded with woodwool board and plastered. The air gap from eaves to loft is very important. 25mm I felt was really pushing it, 50mm would have been better, depends how far it is from eaves to loft, in my case it's about 2 metres. If your ceiling is still in place and you can't slide something effectively into the gap leaving the appropriate ventilation, then I don't think there's much you can do.

 

[Jblakes]

Sorry, yeah it didn't really make sense.

So I've boarded all walls within the bedroom, without removing the ceiling. Before this I put loft insulation down and left an gap between insulation and chimney breast in loft area. So now I've boarded the chimney breast in the bedroom to the ceiling I can feel the ceiling is cold as not insulated above. Can I put some boarding higher up the chimney, what will be in the loft area and push insulation upto it, eliminating this cold area? Or will that cause issues later on.

As for the sloped roof, I've insulated upto the point the ceiling started to slope, thus leaving an air gap, but obviously there is nothing above the thin ceilings boards so again a cold spot.

Hope that clears it up

Regards james

 

[Zebra]

Ah, I see, yes, first point sounds like an excellent idea then. Although if the chimney breast is dry in the loft, I don't see why you can't just push the loft insulation right up to it anyway, why you need the gap. But in any case, keeping the first 300mm or so of chimney warm in the loft will help to prevent cold bridging to the room below.
Second point sounds like you're stuck. I assume the gap between the top of the sloping section of ceiling and the underside of the roofing membrane or tiles is too small to do anything with...

 

[Jblakes]

Cheers for the input, I'm not entirely sure on the sloping part, was hard to see when doing loft insulation, so poke a hole through and see.

So now onto plastering, what's the best finish for lime plaster? I've seem people do steel trowel, sponge, plastic float sponge thing.

What have people done on theirs. Kinda thinking the ye oldie textured look fits the house, not perfectly flat like gypum

Kind regards
James

 

[Zebra]

I went on a one day lime plastering course at Ty Mawr in Wales which I would recommend.
In the end I decided, like you, that an imperfect finish would suit the house, and decided to forego the top coat, instead sponged the float coat.
It's not "ye olde" as in deliberately swirly, as I think that's inauthentic (real 17th century plasterers would have wanted to get it smooth). But it's rough, and quality varies. (You can see in the individual ceiling sections downstairs between joists, where my skills improved!)
If I had to do it over again, I would try applying a top coat. The downside with the sponged float coat is that individual grains of sand are visible (more in some places than others) and a smoother finish might be nicer.

 

[paulc]

So now onto plastering, what's the best finish for lime plaster? I've seem people do steel trowel, sponge, plastic float sponge thing.

On the walls and ceilings I've plastered in lime, I went for a polished finish.

 

[Jblakes]

Cheers for that, what would be the finish for this?

 

[Jblakes]

This is kinda what I'm looking for, well the wife is

Kind regards
James

 

[Lacan07]

Cheers for that, what would be the finish for this?
View attachment 10108

Its a bit difficult to tell without a close up, it could be smooth or it could be floated. You can get quite a fine open textured finish if you use one of those big yellow sponges that you clean your car with rather than a standard plastering float.

Note how they've followed the natural lines of the wall in the above image, there's no need to straighten and the corners are all rounded. But the key to this look is you have to get the finish pretty consistent and flat. So far I've only utilised a floated open textured finish, I'm not sure I'm capable of a polished finish. Open textured looks fine as long as its consistent.

Btw, I'm really sold on that look where you plaster the chimney but leave the mantle brick, it really works.

 

[Zebra]

Here's some examples of my sponged float coat, finished with a car sponge as Lacan07 said. It's quite grainy, some bits are smoother than others.

 

[Zebra]

By the way I too recommend rounding your corners rather than trying to get them square and straight, it makes for a soft look, and it's easier to do.

 

[Lacan07]

Here's some examples of my sponged float coat, finished with a car sponge as Lacan07 said. It's quite grainy, some bits are smoother than others.
View attachment 10109View attachment 10110

Looks fine to me. Floating naturally brings the grain / sand to the surface. Have you had any cracking yet?

How good you want it is very much dependent on how much time you're prepared to spend on it. My only issues so far have been running out of time or being totally knackered and calling it a day.

 

[Lacan07]

Cheers for the input, I'm not entirely sure on the sloping part, was hard to see when doing loft insulation, so poke a hole through and see.

So now onto plastering, what's the best finish for lime plaster? I've seem people do steel trowel, sponge, plastic float sponge thing.

What have people done on theirs. Kinda thinking the ye oldie textured look fits the house, not perfectly flat like gypum

Kind regards
James

If your skimming over wood fibre boards I'd avoid the often recommended Lime Green Solo if I were you. Its NHL and they put accelerants in it so you'll be chasing it from the get go. I'd look for a lime putty based product, I think they're are some that can be used over wood fibre boards.