The Trouble with a Flat roof including fibre glass
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- เผยแพร่เมื่อ 7 ก.ค. 2024
- A look at this Flat roof covering rubber over fibre glass and the problems
Flat roof problems usually stem from the wrong application of poor workmanship, here I have a flat roof with so many issues I cannot wat to remove it!!!! - แนวปฏิบัติและการใช้ชีวิต
I have been using Evalon from Alwitra for many years and it is a great product in itself but the range of metalwork for facia and soffit they produce all bespoke if you want is awsome. I met Mick Smith their technical rep onsite this week he showed me some great stuff they have got, I will get some footage of the install here in the coming weeks cheers Robin
I'm a lead worker and I love watching your videos for tips, your experience and knowledge it would be great if you included the leadwork
In too some of your video & our flat roofs last over 100 years if installed correctly ;-)
It doesn't matter what system you use, if you do it badly it wont work.
o bez 100% agree. People hate felt cause they had them done and they leak few years down the line I tell them that’s not the product it’s the dipshit who put it down. All roofing products has its perks and downfalls.
I've done probably 20 grp roofs so not an expert but certainly know more than most in the space of nearly 15 years or so,It's a good product and not the easiest to install but done right following specs and good practices it lasts,the substrate should be tg osb and layed the wrong way up as it is rougher that side and the joint doesn't meet between the boards creating a channel which the resin keys into,Buy a premium resin like Cure it, double layer 450 gsm or if using 600 gsm bandage all seams joints and abutments,I've also used firestorm liquid plastics torr coatings and felt they all have there sweet spots and pinch points which make them more or less suitable to job at hand,One note an expansion joint is recommended on over 50sq I put them in over 35, I repaired a friends roof which cracked at 48sq so beware and cut the boards as well it's no good just letting the grp flex,
At the end of the day you could buy topseal but if you got a muppet on the end of the roller your f#%@ed
I use topseal,cureit,any resin will work well if you do it right,most don't wet out and or paddle enough, don't cut corners and prep right and they last a long time.
Topseal and cure it same company
The original GRP roof wasn't done properly. It must go on an 18mm thick OSB board layer which must have 2 mm gaps between the boards, if you aren't using T&G, [which you can't always get]. There must be a 25mm gap at any abutment walls and the boards screwed down well with 35mm screws into the roof joists. Then you start the lamination. If it's done properly, it'll last forever and you'll not have any problems.
I've done many GRP rooves going back 20 years, that's long before it was available 'off the shelf'. I've never had a problem or a callback, ever. You can't condemn a roofing material just because you've come across one that has been bodged.
You should see the EPDM rooves I've had to rip up because they've been done badly...
A roofing system is only as good as the bloke/team who install it.
Osb and other sheet material needs an element of expansion gap it's only products like plaster boards that can be jammed together tight, even the tounge and groove OSB has an allowance factored into it in the manufactur process, Great question, thanks for getting in touch
@@DaysOfDarknessUK Sorry for late response. It's for expansion in hot weather. Especially if you're using regular and not T&G Sterling board.
GRP is a fantastic material. It lasts forever and looks great if the installer knows what they're doing and does it correctly - using the proper materials. Many roofers are simply prejudiced because most likely, they've tried to install a certain system and its been too complicated for them or they just prefer a certain one over the other. So they go around slagging off the one they don't like as much. Saying it's useless, it won't last, it's noisy, it's cold etc etc etc..All of which is bollocks, it's just them being prejudiced. Videos like this one, casting aspersions on a material just because they've come across a roof that's been done badly, by some cowboy, really annoy me. I've seen bodged up asphalt rooves, EPDM and other single membrane rooves that have creased and lifted at the joints, that have fallen away on up-stand walls and therefore failed --- many many times.
No roofing system is foolproof, nor is one better than the other, they're all good, the key is not to let a fool install one for you.
And if you have been mugged by some Chancer who made a cock up of your roof. Don't go blaming the material itself. Sue the arsehole who stole your money. If you can find them again....?
@@DaysOfDarknessUK It is essential to use OSB3 on flat roofing. You also need a vapour barrier to stop moisture from inside migrating through the roof but keep in mind . OSB with enhanced moisture resistance (OSB/3; OSB/4) is not waterproof; the term 'moisture resistant' applies to the adhesive binder which (within limits defined by EN 300) will not break down in the presence of moisture. It must be laid with expansion gaps.
I was just wondering why you don't need a gap with T&G OSB substrate? Surely, a jammed together board acts in the same way as standard OSB, expansion wise?
With T&G, would you recommend just glueing and not screwing to aid expansion?
Lastly, EPDM is breathable, so even with a correctly installed vapour barrier, the moisture that does make it through can evaporate. Is GRP breathable in the same manner?
This guy loves himself. Good looking chap. I would too. Good on you mate. Keep waving that hair about. You should definitely get into acting geezer
epdm on a new roof quick easy if you follow the rules and the oldest one i did was 15 years ago still going strong.
Yes mate I agree!!
Terrace over the GRP ? I am thinking of making a 2nd floor deck over a new flat roof (converting from a tiled roof over an extension). Question is OSB doesn't seem strong enough to take a deck on top, so thinking of putting 9mm ply underneath 18mm OSB t & g. Will that work ? Bottom of the deck will be rounded off and have rubber wrapped round it to minimise damage to the GRP. Any better options ? Thanks
Expansion and contraction is what splits fibreglass. The heat that hits a roof is amazing and the movement can be catastrophic to it. I wouldn’t glass a roof over 50 square metres because of the crazy amount of movement. The GRP will give way at what you think is the strongest point where it can’t actually move.
Also thermal noise which seems strange also a problem without expansion joints
Never had a problem with torch on felt.
Gotta use a good quality one.
Anderson Technatorch my choice.
Flexible enough ti withstand our weather. Less fashionable these days but it will come back round when people realise the new tech systems aren't maybe as good as the hype.!
Fibreglass is good but weather and temperature have to be right.
Unfortunately in this country it can be a pain in the arse waiting for ideal conditions so people install it anyway and it fails!
3 layer torch on SBS Polyester. 40 year life.
Can you overlay old TPO with new TPO or is that just a bad idea?
Hello, can you double skin EDPM rubber, if so what would you use the bond them together? Thanks
Built up felt is the best! Good quality materials and a good installer will last longer then all the fancy crap out there..
Agree LA
And cheaper.
Strammitt board is compressed straw wrapped in paper were as woodwool slab is straw like material with concrete mixed in it and very rarely rots were as strammitt boards do rot and was used as a form of insulation and was also used as a board for partition walls but a real fire hazard
Darren Harlow that's where I've seen strammit board, in partition walls. Normally in houses that are non traditional construction.
Thats correct we've stripped plenty of both types in the past and still come across the occasional one now and again 🙂
Very helpful. There are so many single ply membranes available. Is there any particular one you would recommend over others?
Fiberglass can cover any amount of area as long as you install expansion joints and should always be installed on osb3 boards
Absolutely agree about single ply covering. Just replaced a rotted out flat roof structure due to failed torch on felt system.
How to fit a newel post
hi robin i am open to advice. i have a garage roof we have a flat porch and a roof over a closed area that we had felt roofed it was originally years ago corrugated polly plasticy stuff we have an area at back of garage that we have closed in with double glassed windows and doors and downstairs loo we keep our fridge freezer in this area the back door leads into kitchen so the area is quite large. i noted in 2 places that the water pools so when we re roof i am thinking we need new timbers stuff ply wood or what ever its called. i am thinking that over the back living area as i call it the area that leads from kitchen to downstairs loo (there are also and old coal shed that was brick this backs to the side of the downstiars loo i know i am not good at explaining it . The question is we need in the summer to get a new roof done as the felt job was done crapply last time . enough said
i was looking at the rubber stuff but whilst we dont walk on the roof there is guttering that every couple of years will need clearing and a window that i have a window cleaner do that looks over the garage so will have to get on garage to clean it . will the ladders harm the rubber ? will his shoes harm the rubber integrety. the rubber looks nice as neighbour had his done a few years back and he said it was cheaper than torch felt roof. i was then thinking of the fibre glass but i think it will be megga expensive as a really big area to do. my question is do o go for the torch felt which will last not too many years or the rubber which we would have to make sure that any ladder is protected if placed on it not that it would need very often a ladder on roof . we would get a reputable roofing company to do it its not us doing it ourselves i just want a few pointers . I am a nurse by profession and in our house i am the practical one so am doing my research
What did you go for in the end …I’m undecided about roof coverings for my extension . I think I’m going to go for torch on felt because the last roof did 26 years ….I’m not sure about all these single ply options . Probably old skool is best ?!!
Use vapour barrier,most delamination is due to vapour from underneath,or pinholes from lack of resin or shite paddling.
Do that on ply and it won't have long,1-2 years.
how did you get that pitched roof to look like zinc with the upstands? Looks good if the cost is lower than zinc
Hi Henry, the product I used is Evalon by Alwitra, then I had their standing seam welded on to suit my spec/spacing, it's really effective and half the price of zinc, 25 year warranty too, hope that helps
best Robin Clevett
@@ukconstruction Excellent I will have a look. Up stand weld looks good. Keep up the videos they are great.
I use to work for stramit at eye in Suffolk
I swear by fiber glass flat roofs, its bullet proof, but you have to put them down correctly. You can get fake fiberglass lead rolls that allow for expansion, and you should only be putting fiber glass down on t&G 8 by 2 osb boards.
When are people going to learn that you can't beat Mastic Asphalt or Torch on felt if done properly. I'm stripping up more and more of these other systems they are not practical with the English weather.
Agreed Steve.
Hi robin,,I’m no joiner but I’ve got most of the tools with a slight bit of an idea lol,,,I’m in the middle of doing my garden up and want to build a shed,,I’ve just had a 12ft by 9ft concrete base done ready to build a shed on,,I’ve seen a video on TH-cam that Colin fuze built a shed and up to now that’s the shed I think I’m going to do,,but I’m just wondering if you have any videos on building a really solid secure shed,,,I only ask this because the shed Colin fuze built has had a couple of bad comments made on the build about how it’s sat on a course of engineering brick and it had no damp course to keep the damp away from the timber,,,,,,,as your a great builder and joiner,I would much appreciate it if you had any spare time to find and watch the video and tell me if you see any problems where he has gone wrong,,,,other than that,,thanks for you time to read this and home to see some more videos 👍
Hi Bond Bondy!, I will try to check out the video. It's always good to use damp course wherever possible it does no harm! It's a cheap as chips too. Generally speaking a garden room/shed/man cave of that size would be great in 100 X 50 studs with a 12mm sheathing ply, and maybe 150 X 50 joists run on the shortest span with an OSB tounge and groove roof panel if your having a flat type roof, if your going to insulate and line the inside keep some ventilation between the exterior cladding and the sheathing in case of any build up of condensation in the walls, treated sawn timber should be great, Good luck with it, make sure you post some clips of the build!
Robin Clevett cheers for getting back to me robin,,thanks for that,, th-cam.com/video/LP67MAoihZk/w-d-xo.html. This is the video,,see what you think 👍
Explore With us Engineering brick is a damp proof course in itself if done with correct mortar mix. You have different grade of bricks also, seem to recall A grade and B grade. Maybe to do with compressive strength, can't remember. Any how the "A" grade of bricks had a moisture absorbency/content of only 3% so they worked as the damp course. As Robin has said roll of dpc is cheap and good practice to put in. Also engineering bricks are great for building in pad stones under high concentrated load points such as lintels and steel beams 👍
55 mil vinyl is great and much less $ than TPO. Easy chemical seam weld and often just a few pieces for a roof.
Your right builders are going on 1 day courses and then think they can fit flat roof products everyone and his dogs doing them I say leave it to the professional's also there's a lot of miss information about how to apply the products from none professional's on these sites
I've got stramet board or wood wall on my roof. With a hypolon covering. 😦
Strammit board! We call it donkey's breakfast!!
Cannot beat torch on felt been doing it for years
Agree Dave, best system ever.
Hi Robin, excellent video and agree with you wholeheartedly. I'm a builder up in North Norfolk and always find the abutment point is the major issue with fibreglass. Firestone epdm every time.
Keep up the interesting videos & keep doing it right !!!
stramat board is not the same as woodwool slabs, stramat is all straw, woodwool is chips and cement, 30yrs since my first fibreglass roof on plywood and still perfect, its not the certificate that does the job its the person, how did you get on with your cut to falls roof,, still prefer pvc single ply my first pvc job was using the braas pvc and pib membranes in 1980, retired roofer through ill heath. wear a mask when welding pvc,
If you are having problems with roofing GRP cracking try a another make with more flexible resin, it is not the same polyester as for making boats etc. Make sure you apply the gel coat properly as well, GRP is not water proof on its own.
The British climate is not great for any flat roof system hot then cold and wet or snow , ice
Trocal I find the best,
some roof lanterns would look good 👍🏻. haha. I know this video is a year old
Never use rigid fiberglass or rubber on a roof,
Triflex all day long.
Do not EVER use curit on a roof,
We lay a lot of Bauder systems and a tapered insulation is the way forward,
The best roof would be a fully bonded system on a firing roof then an extruded insulation board.
Armourplan dark grey is good with the standing seam detailing.
Can't use ply? Naah that's not right. Don't use marine but cheap ply is great. Sticks better to OSB3 but it splits like crazy when driving in screws and all that will need sanding down.
No gaps, no holes, nothing sticking up and you can't fall off.
It's good for grp,but ultra or desopol don't like the knots that are filled with filler,comes out n wraps around the roller,which is annoying
👍
If your going to use fiberglass or any other roofing products get a highly recommended specialist to do it for you , as you have their guarantee if any problems
theres nothing wrong with fibreglass roof systems if done properly will outlast any other roofing system you have a good point in that osb 3 is the only board approved for roofing systems the roof you have was a poor job then covered over with rubber roofing which is at best a poor job , we are on the coast and have found the seagulls are pecking through the rubber roofs when they catch and eat their prey on them id like to see one peck through fibreglass
Great point about the seagulls and I do like fibre glass but as you say done properly! Thanks for the comment!
GRP is only about 40 thou thick A 3 layer torch on is about 250 thou.(quarter of an inch) No bird will peck through that. GRP will never outlast other systems. I have replaced dozens of GRP roofs. Any board can be used for torch on.
Never happen with mastic asphalt
My fiberglass roof as you said peeled of the plywood substrate,ie load of shit
Because it should never have been installed on plywood in the first place
I think if the plywood was hot mixed first with a coat of resin, then the fibreglass would have worked. Sounds to me like that fibreglass installer put fibreglass mat straight onto the plywood. The plywood would have soaked up the resin from the mat, leaving a dry matting, never gone to work. I’ve watched a lot of videos on TH-cam of people using only 1 layer of fibreglass mat, in my opinion 2 layers should always be used on flat roofs.
You wouldn’t get that with flexitech 2020 installed by a certified installer
Torched on brai or mopped on brai, then a white mop of roofing sealant would last atleast 30 years. White mop every 15 years. Easy 50 year roof.
My next job is a failed single ply roof.
Its not exactly a flat roof is it ? The real problem is multiple materials, with multiple joints, unable to move in sync as conditions require … just thought I would simplify it for you.
Thanks for the comment and spot on!!!!
@@ukconstruction No problem pal … you hum it, we sing it.
Cant beat Armourplan PSG membrane. Been using it for 12 years now. Fibreglass on roofs should be banned. Must Strip off at least 20 failed grp roofs a year .
Sarnafil welded membrane will last 20yr +
Sarnafil recommend their operators to use one layer of torch on under the Sarnafil.!!!!!!
20-20 flexible tec grp straight over it
that roof looks more than 50 m2 .. expansion joint is required. if they build boats out of grp that is in the water 100% of the time a well laid roof should last 3x as long....
The problem with flat roofing is that sellers and installers said 50 years ago "In the past flat roof technology wasn't what it is today. Now a flat roof will last". And then a couple decades later, lets say 25 years ago, sellers and installers say "Flat roofs used to be unreliable. But with today's materials all those problems are no more". So now 25 years later sellers and installers say "Flat roofs used to be unreliable. But with new modern materials and techniques those issues are solved". So what do you think they'll be saying about flat roofs being installed with today's technology in 25 years?
great thought process and I also wonder too, its all about good fundamentals in my humble opinion, what I mean is if you follow really good building practice and adhere to the exact guidelines from the manufactures with regard to their systems and products then there is no good reason that a flat roof will not last the test of time, thank you for taking your time to watch my video and comment on the same, all the best Robin
@@ukconstruction
Yeah, it was a good video. Thumbs up. Nothing wrong with anything you said. All roofs have a time stamp, especially if you don't maintain them. The flaw in flat roofs is not the building practices or guidelines given by manufacturers, I'm sure their specification are based on tried and true methods. The issue is that flat roofs, from an engineering standpoint, are inferior to a standard A-frame or a gabled. It's just physics. The fact is if you use the same exact materials and changed it to an A-frame you'd have a roof that lasts twice as long or more.
You were spot on about that fiberglass. It's far too large an area, buildings shift and settle all year round. Any monolithic roof structure needs to shift with it. Fiberglass doesn't do that, hence the cracking. Fiberglass is okay on smaller areas, like a shed or add on room, or an overhang.
Still the best. 3 layer torch on SBS Polyester system.
we do loads of fibre glass and put the fall on with firing pieces, then 11mm OSB followed by 120mm PIR, then 18mm chip, the trick is not to get the joins and 18mm and 11mm sheet joins matching and also to gaffa tape all screws and joins. Its quick do the actual fibre glass but like many things its all in the correct preparation.
....but that is not a warm roof though.
Sounds pretty warm to me. Apart from a vapour barrier, what’s missing?
@@edwardfrench9925 Nothing missing, just no decking must be on the insulation. Only the waterproof covering. The building regs guy would not pass this roof.
Birds love to peck rubber roofs
It's crap you can't beat bauder or Langley felt systems if done properly will last 40yrs +
It's a timebomb cos every Tom ,Dick and Harry doing it.
U R worried U don't look good on TH-cam........FYI U look pretty good to me.
Nothing wrong withe Fibreglass roofs, the main problem is crap job..
Thanks for sharing your knowledge with us. Keep on posting your work not many people have your experience.
Hi Richard, kind words!!! hope I can offer something thats useful, many thanks
Robin Clevett
True word's Robin not kind 👍
I'm most certain that you can give a lot of your knowledge that you have gained from the number of years you have been working.
That is invaluable to people who want to learn so thank you again.
"Lots of issues around it" such as? Apart from the fact that it's best [though not essential] that you use OSB as decking layer, which you do for EPDM and all other single membrane systems as well..? There aren't "lots of issues" at all - that's complete nonsense. There are no more "issues" with GRP than there are with anything else. You were unlucky and came across one that was bodged, that's all there is to it.
I thought you could use ply for epdm's , seen it used many times with no problems . GRP is unreliable over large areas as well i've heard . doesn't cope well with changes in temperature leading to cracking
Sadly, OSB is actually the lowest rated decking material, of all standard materials. Many manufacturers wont supply high wind warranties over OSB
@@RoofingFacts "Rated" by whom? Even if that were the case, how does that add weight to the claim that there are lot's of issues around GRP?
@@baxterenrife ASTM, for starters. ANSI isnt very fond of it either, but are forced to remain neutral so they just put out testing standards for the field which OSB can only just barely pass on the low-end.
Seriously, have you ever done a pull test on OSB? you would be lucky to score over 400psi. 400? a half rusted-out steel deck can usually support 400. You could literally lay down flat rolls of 22 gauge and nearly get that level of support.
Carlisle and Versico wont even give it above a 90Vult rating for the warranty (despite the fact they have options up to 130mph)
IB requires your fastening to be at 6 inches on center (double that of plywood or steel decks)
and it goes on, to where some will require double perimeter sheets, doubled adhesive patterns, or shrinking down your roll sizes to double or triple your number of fastening seams.
OSB has the lowest supportive strength for adhesives and fasteners of any major deck type. That isnt speculation it is proven fact that is as easy as googling "typical psi ratings for decks" to find if anyone cares to do research. The best deck types are usually steel or concrete. below that is plywood, tongue and groove, heck even lightweight concrete was stronger and at the bottom of it all is OSB, with the lowest supportive strength.
But I guess that's the difference between residential and commercial applications is having to constantly bear in mind codes and standards to a high degree. Most residential consultants/contractors have never heard of Vult or Vasd whereas high end work requires you to do the math and look up the standards every job.
On a typical 55mph application (lowest of the low) OSB is fine. and thet most common because it is easy and cheap. however it still exists as the worst of modern roofs.
@@RoofingFacts So you would advise using what form of decking for fibreglass rooves? Also how do your speculations add weight to the claim that 'there are lots of issues around GRP'? Given all you've said is: "OSB bad"?
Fibreglass and EPDM are both crap, they're ok for a small dormer but that's about it. I'd have felt over either of them all day long, but in my opinion, and I've used them all....you can't beat PVC single-ply and alwitra's right up there with best of them.
Robin knows his shit!
Just going to inform you strammitt is not straw and cement , strammitt is straw wrapped in paper the board you are referring to is not even straw with cement it’s wood shavings with cement and is known as wood wool slabs
Very disappointed in you
Fibreglass is crap !
Known that for 30 years.
@@MrFlatroofer What is your experience of fibre glass? Was thinking of using it on a flat roof ( and balcony) for a 20m2 room..
OMG !!!! Ads about losing your job, I lost my job too !!!! You don't see me crying about it on a video !!!!!! Shut up already !!!!!