I was thinking Liquid Nails would hold it in.

Brilliant tip. Thanks.

PtolemyauletesXII temporarily just nail a couple of tile battens over it but don’t hit the nails right in

So much quicker to drill in 40mm galvanised steel screws down both sides of all the rafters first so they project out 20mm from the rafter face, spaced at 400mm centres and 60mm in from the face of felt. Then cut your PIR board to size and simply push it into place onto the projecting screw heads resulting in a mechanical friction fit where the sides can then be filled with foam.

Gapo tape is what you need.

Dear Ben Clarkson, some people use Rockwool. Is that fine or is that bad?

@@alikhan7903 Bad, and most probably against regulations

Ben Clarkson amazing tip thank you! I’d never heard of these but they cut the dust by 99%

Alu foil tape best

That's been around for years lad

Mohammed Muhammed depends what country, it may have been here🇬🇧 for years but small companies have only been more commonly using it in the last few years

Is that more pricey?

@@scorpionnetherrealm8937 not sure, I haven’t had a quote yet but know from cutting and fitting standard board into rafters that weren’t perfectly straight, it was very time consuming and dusty

Will try and get round to a video soon. Project on hold due to budget and apparently "not a priority". 😔 got plans and sketchup done though.

well, you do have quite a few projects on the go so I can see Restoration Wife's reasoning hehe but yes, you're dropped a few hints about it and got a taster from your garage to office project in your last house, so would be fab to see those plans even if it doesn't get built for another year or two! :D

pro tip : you can watch series on kaldroStream. Been using them for watching loads of movies these days.

@Will Mohammed yea, have been watching on Kaldrostream for months myself :)

Would love to know the answer to this too!

more insulation is always better, as long as you have good air flow to stop condensation.

Fortunately we have a company here selling seconds and returns from building sites so we saved well over 50%. Won't be many years before it pays for itself considering it was just lath and plaster there before!

Good stuff, decent content

The Restoration Couple whats the brand of the two insulations you Used?

I Build It Home gghbn

The Restoration Couple is its seconds and co.? When i costed it there wasnt a huge difference between that and insulation for less for exampleo Es

chris jones ideally put counter battens over the insulation before plasterboard which leaves cavity for cables and pipes. We ended up doing a combination of this and also bringing it through from eaves using conduit and taping airtight. Ideally try and keep all on the warm side

many thanks

The loft is ventilated via the eaves!

I can’t imagine it would be a problem, especially by the time you have any vapour barrier and panelling up.

The Restoration Couple Thank you so much.

I've used loads of cellotex in my house and took the offcuts outside and tried to burn them on a bonfire...they will NOT burn without a lot of effort trust me...that stuff on that tower must have been an older combustible type..not this stuff.

I am very similar and like to keep things nearer to how they were. This is one reason why we haven't internally insulated our walls anywhere in the house. For me the risk is to much of a concern. With the loft there is far less risk as we are just replacing the old ceiling and there is always air flow above, same with the insulated ground floor. I have just filmed a video about some of the risk of insulating older houses so will be online soon. TRC

Same here we know of many people that have had their cavity walls insulated but it is not something which we feel is sympathetic to our house. I am looking to start a project in the next few months to convert the cold, badly boarded out and loose filled insulated loft space into something we can use for storage. I have watched some of the vlogs of your loft project and it has really has filled in a few gaps in my knowledge.....although I am not looking forward to getting the materials I need through a small ceiling hatch. I will keep my eyes peeled for that video you had mentioned and thank you for taking the time to reply to my question. Mandy

The Restoration Couple Hey there. Started watching your channel recently as I’m starting to renovate a house around the same age ages yours looking at the vids. I have took down all the ceilings and have took most of the old plaster off the walls as it pretty much just fell off everywhere in the house. I was planing on studding all the exterior walls and insulating them and plasterboarding them. Would you not recommend this or can you leave and air gap behind the stud and insulation so that if any damp does arise it should dry. Thanks.

There is a product called gapotape which works better than expanding foam. it also allows the timber rafters/joists to expand and shrink. Unfortunately, it's rather expensive.

Yes that’s important. 50mm between insulation and slates. Hence why the rafters were extended. 👍

If that stuff dont give you cancer .i dont know whats in it.. but its in the top three of the worst jobs in the building trade. I hate it.

@@TheRestorationCouple - looking at following your exact process for my re-fit - but I've seen recommendations of using a vapour barrier also - did you use any barrier system (i can't see it on the vids) if not, why not?

@@markwilson2991 Yes vapour barrier in this case was the foil of the boards which was taped.

@@TheRestorationCouple many thanks!!! keep up the great work....I think a knighthood is in the offing - for Services to Renovation and Lockdown Sanity

Foil tape to do seams before plasterboard. More detail in a video a couple weeks back in teh garage conversion.

I have a little opinion on this I live in a climate that had 11m of snow fall over the winter and in summer is up too the mid 30s and sometimes hotter to stop this we insulate the out side and only the habitable space by this I mean when we make a roof you see the rafter and close boarding then there is a vapour barrier insulation then a trepizoidal shape timber then a thick water barrier then a batton cross batton then a tile! It looks good as tou can see your rafter and don't lose space I guess only good if you need a new roof!

It’s just a traditional slate roof. We intend to re roof next year but all that can be done externally. Not come across lime mortar under slates. The room was plastered with lime over large if that’s what you mean?

... and when we need to re roof the house next year?

The Restoration Couple Re roof...you mean taking off the roof's wood sheathing. Well of course that would be problematic. I thought you meant the the water proof sheathing which wouldn't be a problem. Oh well different approach to fixing a roof.

Yeah, here in the UK the normal roof constructions are natural slate or tile on timber battens, no sheathing/ply type covering. Therefore all slates would be a nightmare to remove and unable to be reused plus less companies about dealing with sprayed foam than is the US. Assuming that's where you are? Anyway, the place is warm now so all ended well. :-)

The Restoration Couple very interesting about roof construction methods in the UK. Thanks for the info! Actually, I am in US Florida. Timber frame homes not many very expensive. Stick frame and truss for roof with plywood sheathing over here and in Canada too. South Florida concrete block wall with wood roof truss.

Best to leave 25-50mm just be on the safe side just incase the membrane if any is compromised.

Just used gun grade type adhesive along the ends. Worked fine as insulation itself was secured. 👍

Good question. I'm looking for a water absorbent polypropylene membrane that I can staple on the outside face of the insulation. This will absorb small amounts of water and this can evaporate later into the air gap. Haven't found anyone who will sell me 150m2 or so yet.

Sorry no need to reply I found a comment which addresses this. Yes to all

Into timbers. It only really needs to be enough to hold it up before the plasterboard goes over as that will secured both. Assuming you are using separate layers rather than bonded.

Yes using separate layers. Cheers buddy.

yes this i want to know. Where is the breathable roofing felt? Are there air gaps in the soffits? Can ventilation flow (prevailing wind side) through soffits and slates up to ridge board and then down other side of roof?

Ours was only 50mm so long screws were used. I would suggest battening over the insulation to give you a space for cables and easier to fit pb. I would try some long landscaping type screws to fit battens and then you can use standard drywall screws for the boards.

@@TheRestorationCouple Thanks for the reply. We will look into battens.

I mean ventilations extractor

Should be fine yes.

7:05

It’s double sided.

Watch the latest video. 👍

@@TheRestorationCouple - Im interested in this comment - which video do i need to watch? Thanks - Great work

Spray foam insulation.

Insulating your roof from the outside does a pretty good job of it if it's not done yet. 200 mm thick polyisocyanurate plates wrapped in foil do the job pretty well. Saves you a lot of inside space as well. That's what I had to do for a full renovation and it's brilliant.

If flush with the underside then just strips of batten fixed to underside of rafters? There are clips but strips of batten just as easy if only storage area.

@@TheRestorationCouple thanks! I'll give it a go :)

The trick with stapled gaffer tape works well even longer term it also seals the air gaps

Jam them up with wedges them expanding foam.

Plastic garden mesh netting, pulled tight with just a few staples each rafter

ha? you care giving us more insight plz ? thx

@@ioncv5295 if you use a expanding foam such as insta stik between the Kingspan boards it fills the gap, therefore cold air can't pass through, therefore stopping cold bridging as the gap is insulated as well, also good for a vapour barrier.

Minimum 50mm gap for regs.

The foil acts as a vapour barrier and reflects heat rather than absorbs it like untreated poly boards would. Also need to add a 25-50mm air gap between these boards and the upper roof tiles if no membrane installed.

Boards in the same way with counterbattens under to create cable cavity.

Just screwed through the 50mm boards into rafters. You can use battens if you need to run services which we did elsewhere.

The Restoration Couple probably a stupid question but are the rafters easy to find under the insulation? any tips if they aren’t?

Never mind ... saw the info at the end of the video, and found them on eBay :-)

Marmox washers

eBay

Or an air permeable membrane as we just fitted.

@@TheRestorationCouple can you link tht video, or is it this one? You've got so many and I can't seem to get them in the right order. I'm looking to do a similar loft. It's floored already, but no vents in the soffit.

Ian Mc Namara latest three or four videos all show roof.

Simon Williscroft did you ever find the answer to this? I'm in major need of washers like this too. Or does anyone else know?

@@HostilePride They are backer board washers.

It may be possible to achieve similar with multifoil. However I think it ideally needs an air gap either side or at least one side, that would have meant counter battens on every rafter/stud. We purchased a bulk deal of 40 sheets and I believe this worked out the best for our £££'s. Also some BCO are a little funny with multifoil products so worth confirming they are happy first.

It's true you need an airgap, but that can be provided in the rafters and I believe it should still take up less space than most PIR board - some multifoils say they can be attached directly to the rafters with 50mm thick counterbattens between the foil and the plasterboard, others say the plasterboard can go straight over with the foil pinched between the rafter and the plasterboard (which, admittedly, I find rather odd). Some multifoils claim to have LBC approval, so I didn't think that would be an issue. Besides, if you're renovating and adding insulation to an existing roof, I didn't think it was necessary to involve Building Control? Anyway, your solution will I'm sure give results that are at least as good if not better than the second layer being multi-foil and since you got a discount it's a no-brainer. In my case I'm researching insulation for the 250 year old limestone cottage I just bought; the roof is only from the 90s, though, and the insulation is just 150mm of rockwool inbetween the rafters. The main bedroom is in the roofspace though and so this isn't enough. I've therefore had my chippy rip all that out and I'm going to get him to put in PIR and probably multi-foil. Two layers of PIR would lose too much space inside the room. A couple of examples of under-rafter multifoil installation instructions: www.ybsinsulation.com/wp-content/uploads/2015/08/SuperQuilt-England-All-In-One.pdf www.just-insulation.com/reflective-multi-foil/tlx-silver-30mm-mult-foil-bba-certified.html

I suppose if you were struggling with ceiling height then multifoil might help. However 50mm battens over M/F would be the same as the 50mm PIR, so you would have to loose the air gap. Either way like you say it will certainly do the job and multifoil quicker too. You may get away without BC if you are replacing existing but I am pretty sure the small print says any major changes to thermal elements or along those lines. Reason is probably more about vapour control and enforcing airgaps above insulation.

Well yeah as said some types - the Superquilt for eg - don't seem to need an airgap and therefore no battens, but I do find this a little odd. Seems strange that you can get effective insulation when the only insulation where the joists are is some multifoil pinched between joist and plasterboard, which is also going to squash the air out of that section. I think, though, that one advantage of the Superquilt is that it's more of a contiguous moisture control layer as instead of sections being just taped there's a 50mm overlap between already large sheets that's then taped. I'm not sure though. This has been a useful exchange as I already have a Building Control notification in for other aspects of this project so on the back of this I'm going to give them a call tomorrow :).

So I had Building Control over about other things and spoke to them about multifoil and insulating the roof. You're right, they're not keen on multifoil and it might have been difficult to get them to sign off on it. What he did say, though, is that since I'm using 100mm Celotex or Kingspan between the 150mm joists I only need a layer of 25mm PIR under the joists to meet Part L requirements, so I said I'd do that. He also said that because the room was considered habitable before I started work, this upgrade work doesn't need to be approved by Building Control anyway. So I'm in the clear on both counts: I'm going to do it so that it meets Part L standards for my own benefit, and I don't need it to be signed off anyway. I'll most likely use PL4025, the plasterboard backed with 25mm Celotex, with the vapour control layer provided by the GA4100 and tape. Now to look for the cheapest supplier of the stuff! The inspector gave a couple of useful tips. Firstly, he suggested pushing wedges into the layers of felt from the inside to ensure airflow - he said they've found many roofs constructed in the 90s like mine don't allow sufficient air through. I just need to find suitable wedges now. We also mentioned we might be using PIR board in the new stud walls we're installing throughout the house, and he said that they've found PIR board can often act as a diaphragm and can magnify sound instead of deadening it. So he suggested using rockwool instead - which at least is cheaper!

No just cut from full size pir sheets. Cavity boards are usually thinner and smaller.

@@TheRestorationCouple What depth PIR board did you use/recommend?

50mm. Our rafters were 75mm hence why I extended them to 125mm.

Thanks for the reply buddy. Just seen your other video explaining how you extended the rafters. I have a material under the tiles (felt type). Would I still require the 50mm gap? Ideally I don't want to extend the rafters as I will be reducing internal roof space however if it needs to be done I will do. Would I require a vapour barrier? I live on a busy main road so sound proofing is high on my list. Acoustic Rock Wool 50mm a good idea? With 15mm acoustic plasterboard on top? My plaster board will be fitted flush with the rafters (don't have space to install further insulation on top like you have done).

@@TheRestorationCouple Hi, I'm going to the the same insulation as you in my attic and also have 75 mm rafters. If you extended them to 125 mm and installed 100mm insulation then you ended up with only 25mm and not 50mm gap between the roof. Am I wrong? Please help!

@@michadzianach6512 at the time there was no roofing membrane so there was 50mm between slate and PIR. Having now completely replaced the roof using a fully air permeable membrane, there is not the same requirement for the 50mm gap so more like25-30mm. Always good practice to have some however many membranes will allow you to reduce that quite a bit as the whole roof becomes vented. Roofshield is what we used and rated highly.

It’s called a warm roof..basically the insulation is on top of the rafters then vertical battens, then horizontal tile battens..

Yes, however if you see the current videos that is no longer the case. 👍

You could drop the flatter part of the ceiling to create a small void. Or do a warm roof instead.

It’s for a garage conversation on a sloping roof with restricted head height I plane to 100mm in between beams then 50mm over top then roofing battens then plasterboard just unsure on inserting lighting

D MARSDEN of using batten that will only give you 25mm void. There are some slim led lights that will suit but may need a little more space. Batten service void works great for all the cabling too.

Well if the roof doesn’t leak and it has been up there for 120 years it’s fine for a couple more. It’s also a huge job and costly so better to wait and do it properly. 👍

If the roof insulation breathed it would allow condensation to form on the underside of slates! The foil face will be at room temp so not cold enough for a dew point. Agree that natural insulation would be preferred but you also loose 2x the headroom. When it comes to roofs there is not much difference between then and modern day, you still have air space above so not risky like internal wall insulation.

TRC you are fine (as you know) - in fact you need to tape the joints to make it as airtight as possible. Not sure what the previous comment from JH was about, you wont get any condensation in the cold roof void behind your new insulation, thats the whole point of making it airtight. Granted, if any warm moisture laden air makes it into the cold void then yes condensation may occur, but if there is air movement back there then it should clear. The problem with posts like yours, is that it attracts comments from the 'I know a little and think I know the lot' internet knowledge gang! Good luck with the projects. Enjoy watching them.

I think the problem might be, much more than worrying about actual condensation, just moisture in general. Moisture needs an escape route, or some kind of air flow, or rot and mold will develop. In North America forced air heating systems generally solve this, but in the UK I come across terrible mold and mildew problems all the time. I admit that I am not an expert in house envelopes and that sort of thing, but it seems advisable that you have some kind of ventilation in your loft to avoid moisture developing into worse problems.

That’s why what ever insulation you use you need a counter batten to lift the tile lath off the felt or membrane. It will condensate what ever you do. I prefer wood fibre or wool. Mainly because I like breathability and diss like chemicals.

This is true if there is no air flow. Common building regulations in the UK state if you insulate the roof space in this way you must leave a minimum air gap of 50mm between the roofing membrane and the insulation In combination with a vented sofit or ridge system or both depending on the design of the existing roof. In short moving air doesn't have chance to condensate.

Top floor is great now. Rest of the house not so much, that's the trouble with old solid stone walls.

Warmest room in the house. No radiators yet but barely needs them even at the moment and in our old stone house that’s impressive!

wow! are you in the uk or ireland?

I live in Ireland and the insulation you see here is plenty to keep any house warm - In Ireland the BER rating would shoot up with this insulation job

The ventilated space is abobve insulation and below slates, this is the 50mm required for airflow. The rooms are actually very stable with regards to temperature as the solid stone walls help regulate and the insulation keeps it cool in Summer. Far better than before when it would be like an oven in Summer and single figures in Winter! :-)