Ventilation Cold flat roofs Abutment vents Making V purchasing them?

[@ivanmullen3015]

Like the idea of the liquid application forming an integral part of the unit

[@nb6011]

The liquid one looks great. I will use your idea on the next one i do.

[@stewartsummers4587]

Great info as usual , as a general builder and roofer in very wet north Cornwall this would be a great product to keep in stock and not expensive considering the internal works could carry on , many thanks for the info Steve 🥟👍

[@SteveRoofer]

You'll find out if you've got this product with you in the van you will use it for so many different things as well. It is so good

[@bikerchrisukk]

I really like your timber angles with vents, if it's quicker than vent mushrooms it's a winner. 👍 Thank you for sharing your knowledge.

[@SteveRoofer]

Glad you like them!

[@anglianroofcare4616]

Hey Steve. We have used that abutment vent and we had the same issue. Very flimsy and just felt like it was the weakest link in the roof. Does the job... but even now we look back on it and say 'never again'. Just felt cheap. We used the 1m OFVs onto the upstand but we finished it off by making a length of ariss rail at 45 degree. Think it was 3 x 3 inch. This made sure that when we done a lead flashing we had no standing water. Worked really well and felt solid. Loving the videos.

[@SteveRoofer]

Thanks love to see some photos

[@craigwhittaker2175]

Hi Steve. I wish you worked in the North West area! Great video.

[@SteveRoofer]

Maybe one day!

[@girlatendofrwjishot]

My roofing company in Utah, USA couldn't find anything decent on the market so we've begun using perforated metal z-bar and a custom bent-counter flashing which cleats into the z-bar. Very cost-effective, readily available materials without too much fabrication needed, and it's all metal, holds together very nicely, feels solid, and flashes into headwall same as any other counter flashing.

[@andrewpettet2286]

Great videos and very interesting. I have found a low profile led fitting 230v which would fit in to a lowered 25mm ceiling to give the air tightness and stop the condensation.

[@SteveRoofer]

Sounds great!

[@marksfreeyoutube6159]

Great engineering, as usual

[@operarter]

finally fund my case here. Thank you!

[@shorecroftkayaks1566]

Hi Steve, great video. Can you give me the link to the other video you referenced at the start, can’t see it

[@ianbatook3938]

Thanks Steve. Excellent videos from London Flat Roofing. Real professionals are hard to find , and there are too many expensive chancers out there. DIY is the favoured method if any doubts, hence over the months I have been learning from hundreds of points of view for the flat roof I have to replace. This ventilation abutment vent will be used on my new warm roof. I am insulating both the ceiling void with a 2'' air gap at top, and above the joists with 9mm and 18mm ply, with vapour sheet and phenolic insulation 70mm due height restrictions. EPDM top coat , and I'm going for stainless steel gauze 5mm gaps bought online and a wooden home made abutment cover over the top which will be liquid rubber coated black and silicone sealed. ( 8 metre run to make there. 4x4m roof) Total cost under 4 grand.

[@SteveRoofer]

Sounds good can you send me over some photographs?

[@bonbons34]

Liquid version looks more smart in my opinion

[@phil4605]

Another cracking vid and homemade all the way for me as more durable. Those placcy ones looked v.brittle.

[@mohammeduddin4340]

Hi Steve. Just wondering if you could provide the link of the smaller black vent in your mk2 design please. Thanks

[@thetravelboss7820]

Great Video Steve, I am building an extension that will join onto a static caravan. Its a cold flat roof and Im trying to figure out how to ventilate the roof where it meet the caravan. I dont have the luxury of 150-200mm updtand so how can i use an abutment vent to ventilate the roof properly?

[@SteveRoofer]

Without further information I can't come in there's normally always away unfortunately you normally have to make the vents though

[@thetravelboss7820]

@@SteveRoofer I plan on buying the roof directly to the caravan under the existing gutter. The rafter are made from 2x5 with 16” centres on each joist. They span 2.5 m long. I will you 3” noggins and 3 “ kingspan to allow 50mm airflow. But the air had nowhere to go as it joins the caravan. I seen the test you did with the plexiglass, smoke and fan. I plan on using EPDM to Cover the roof and want to avoid cutting 20 holes in it for breather vents. Any idea of another options?

[@gwilko6452]

First option everytime. My company often does that detail with Armourplan metal over the fascia vent and then one into the wall. Cut a cover flashing and weld to the metal and seal into wall chase. Jobs a good un 👌

[@lorrainegirvan4180]

Help Steve! We are getting a flat roof and will need these abutment vents but I don’t understand where the air flows to . If the vent is covered in lead, where is the moisture going to? In your video you have a vertical upstand but ours is a totally flat plywood board . We were told to cut a section along the plywood at the wall and put these vents on. We have old rough cast render so we have to dig out the wall to put lead in, then it will come out over the vent and over the roof . I imagine it will look really messy.

[@SteveRoofer]

Its vented because there is a continue open area if installed correctly and yes that don't look that good

[@rhysfisher6976]

Could you do a video of how you make your abutment vents out of timber please?

[@SteveRoofer]

This one does show you how to do it out of Timber. If not, there is one or two out there that I've already done just search the word abutment vents in your find them

[@rhysfisher6976]

@@SteveRoofernot sure if I’m just being a bit thick but I can’t find the video. Any chance you could share me the link please? Thanks in advance. And thanks for the great videos too.

[@louisfroment1879]

Hi there, thanks for you videos. What about contrebatton the flat roof? thinking of doing this on a project. It will also help ventilation around velux??Could I get your opinion on contrebatton.Regards

[@SteveRoofer]

Yes counter batten the roof for ventilation is the best way

[@louisfroment1879]

@@SteveRoofer Thanks a mill best regards from Dublin

[@giuliocesareghermandi]

I think many of your concerns with the “off-the-shelf” product are related to the quality of that specific one. Have you ever tried working with Airtrak Ventilators?

[@SteveRoofer]

No but I will have a look and get back to you

[@topG243]

Where did you get the pre-made abutment vents?

[@HampsteadBuildersLt]

sorry don't remembe

[@scottwagstaff7900]

Can you mix the two - I prefer the "lead" finish in period buildings with but the profile of the liquid.

[@SteveRoofer]

I have an example of a lead one we did coming out in about three weeks it looks amazing

[@Freddo69]

Thanks for the video Steve! Question for you if that's OK. I have a house with an extension with an old flat roof that's uninsulated and unventilated. It appears to have initially been built with a felt roof (circa 40 years ago) which has been encapsulated by rubber 10 years ago. There are no leaks. In your opinion is there no way to correctly insulate it without taking the roof off (and therefore may as well convert it to a warm roof?) It is closed on 2 adjacent sides (1 is the high side). I considered whether i could remove the ceiling and install insulation and VCL, with a 5cm air gap above the insulation, while installing soffit vents on the open sides but based on your previous videos I've come to the conclusion that this is high risk. Thanks, Steve

[@marknadin770]

Liquid one👍

[@SteveRoofer]

Good choice!

[@shrekshrek413]

Hi Steve thank you for your video I’ve asked around for an abutment vent at most of our local epdm suppliers They don’t stock Also the guy doing my roof doesn’t know what one is Having watched your vids I explained it to him He said yep that makes sense But where can I can buy them from pls

[@logik100.0]

Makes me want to stick with a warm roof.

[@northeastcorals]

If only we always had the head room :(

[@soundofstockwell1731]

hi steve i have a flat roof that is also a terrace it needs a new cold roof due to height limitations if it has mushroom vents its use as a terrace becomes impractical could this type of abutment be used front and rear thank you for through ventilation ? thank you

[@SteveRoofer]

Yes, that's exactly why we use them

[@tomaytotomato]

Hi Steve, I am looking to do redo my flat roof on a remote island in the UK. The place gets really stormy, and as its coastal you get horizontal rain at time. Would an abutment vent be advisable, what are the chances the wind would push the rain or moisture up through the vent an into the flat roof cavity?

[@paulwinward4680]

Hi Steve. Thanks for all these videos, they are brilliant. I am building a small flat roof extension with Parapet walls and a lantern and basically can’t decide which roof coating to go with. Rubber EPDM, liquid rubber or Resitrix. Which would you opt for? Thanks

[@SteveRoofer]

EPDM would be my first choice Resitrix second choice

[@hooters28]

Definitely your version Steve. The other is way too bulky I think. Plus if there’s a chance it could snap in the cold wind why bother with it at all?

[@SteveRoofer]

Thanks

[@Naavya106]

Hi sir ,from which shop i can buy that vent.

[@brianhewitt8618]

agreed, it looks crap, the plastic one will fail with the first window cleaners foot, and the timber option is much stronger and neater and ive had to do similar to that myself in the past

[@SteveRoofer]

Agree

[@chapman9230]

How do these fit with the cavity trays where you have a cavity wall?

[@dryfixpreservation]

Hi Steve, I'm wondering what's the surface area difference between the two vents? Personally I think your bespoke design looks a little small ans too tight to allow good airflow compared to the deigned product.

[@northeastcorals]

Are you referring to the Facia Vent strip he uses? I was reading on roofs with a pitch below 15 degrees you should use a 50mm vent strip rather than the 20 odd mm ones commonly used on higher pitched roofs. Link: buildingcentre.co.uk/media/_file/pdf/6584_pdf4.pdf But then again I see plenty of other products detailing a 25mm gap such as on here: www.nicholsonsts.com/sites/default/files/files/standard/AIRTRAK%20Feb%202017%20HR.pdf

[@andrewhunt3648]

Rather than doing all of this could you not just run battens across the joists and fix your OSB on top allowing the airflow to go across the roof perpendicular to the wall you are joining to?

[@northeastcorals]

Yep if you have 2 sides that don't but up to a wall etc then that would work fine.

[@154electrician]

Hi steve a quick question , i have a pitched cold roof covered with sarking boards , its currently getting redone but the sarking is staying , should the membrane be breathable or non breathable ? Thanks for any help

[@HampsteadBuildersLt]

depends on a lot of things but probably air open and breathable

[@154electrician]

@@HampsteadBuildersLt thanks you for replying , they have installed a non breathable membrane by mistake but say the will fit 6 tile vents and that should be fine , in your opinion will that be adequate?

[@HampsteadBuildersLt]

@@154electrician hard to say as it's all about how much humidity you make in the property and how much gets though if you want to send over some photos of the roof and info Ill have a look

[@154electrician]

@@HampsteadBuildersLt will do thanks again

[@colmpower5197]

What is the liquid used? epoxy, fiberglass resin or something else?

[@SteveRoofer]

Its AH25 but now not on the market any more

[@mohammadsamin218]

Hi Steve, I wonder if I can trouble you for some advice. Ive just had my flat roof done using epdm. However, I noticed that the epdm surface clearly has what appears to be raised screw heads underneath. Almost like they could have gone in another few cm more. They have not yet pierced the rubber but is this normal, plz. ??

[@SteveRoofer]

Not good please send photoes [e-mail]

[@ralphhardie7492]

Great thanks

[@itstamoo]

hi steve, can you have a parapet and a cold roof , is it possible to ventilate ?

[@SteveRoofer]

Yes not a problem just use abutment vents

[@brickrightbuildinglandscaping]

New to the channel just subscribed love the knowledge your willing to share brilliant mate Justin @ Brickright 👍🧱🧱

[@htapsell]

Liquid one for sure

[@ANDYMCNET]

Your own version MK2 is defiantly loads better. Please may I ask how little of an air gap from the wall can I get away with? =)

[@Danmayes88]

Fix a 50mm arris rail on top of the vent, then dress the lead over.

[@shawnfowler1425]

I have a question. On a cold flat roof how do you determine how much ventilation is adequate? I have a roof i am redoing and after seeing your videos I want to add venting

[@martynmongan9123]

A flat roof should be provided with 25mm continuous ventilation on opposing sides. This equates to 25000mm² per linear metre. Cold roofs should be avoided where possible and a warm deck should be constructed.

[@SuperMickjr]

Hi Steve quick question I'm reroofing an existing tile roof that has to much of a shallow pitch going to strip it back ply it and pvc membrane on top ideally I want to put a vapour barrier down and 30mm foil back insulation and make it a warm roof there's no insulation between the joists but there's an insulated plasterboard as below the joists would u consider it OK to carry on with a warm roof construction thanks

[@guyanagold4869]

Use natural slate & permavent easi slate upto 12 degrees

[@SuperMickjr]

@@guyanagold4869 hi Chris no tbh there's to much detail on the roof boiler pipe sky lights soil pipes pvc is the best option maybe standing seams

[@guyanagold4869]

@@SuperMickjr liquid system then. Warm roof needs 120mm insulation though. You could fill joist with foil backed. Put 30mm above rafters then double counterbatten & vent

[@SuperMickjr]

@@guyanagold4869 no I'm a pvc man I hate liquid products... Any insulation about the deck is a warm roof 30mm or 120mm the insulation really more so the pvc goes down better rather than warmth reasons can u see any problem doing what I suggested u think there be any problems over the insulated slab ceiling

[@martynmongan9123]

Definitely do not have insualtion between and over, this creates a hybrid roof which can create interstitial condensation as the insulation between lowers the dew point. Where a warm deck is constructed it should be the only form of ventilation, not a mix and match.

[@pb3152]

Hi Steve is it possible to contact you via email, I will be constructing a flat roof soon on my new extention and was after a little bit of advice before I start the roof. Cheers Peter

[@PeterWest70]

Instead, consider an aluminum 90° say 2” (for wall) and 2” (overhang) places flush with the board but allows air to vent- and it’s rust proof!

[@SteveRoofer]

Sounds interesting

[@harrydurham1]

I’ve been looking at different methods and options to construct my flat roof I am having on my house and I wanted to get the ventilation on it spot on (seen some many roofs fail due to it). Saw your channel and your spot on with all your information and facts on flat roofs and ventilation and love your version of the timber upstand as the plastic ones are rubbish (hence how I found this video and channel). A customer ask me about doing a garden roof for them and showed me a KZbin video of a garden room company constructing one and I must say it looks like they do great work. I noticed they do a version of a hybrid roof (link to the video explaining his roof kzbin.info/www/bejne/e4uplHuZrcd5mKc ) and wanted to get your thoughts on it to see if it would work or not, I’m not sure it would but I may be wrong? Many thanks

[@garvielloken3929]

🤔

[@ph111hud0]

Steve can u help, i am about to insulate my garden summerhouse, its going to have a hot tub inside, do i vapour barrier the ceiling?, its a cold flat roof, ive vapour barriered the floor and the walls so far but was thinking about the ceiling, am i best to leave the barrier and just have thw insulation boards ?. Il be using 25mm kingspan, the depth from the roof to the bottom of the rafter is 120mm. So do i put the board tight to ceiling roof or to the plywood that ill be using to board the inside?.