Anybody had anything to do with resin based coatings or other such remedys for flat roofs instead of that dreadfull material called roofing felt which in my opinion should be banned from use exept for dog kennels and pigoen lofts.
Mal.
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Mal, Your'e quite right in your assesment of felt roofs. Flat roofs also have never been a success and the old principle of a pitched roof to enable the water to run off quickly is the only way. The experience of trying to find where the leaks are coming from can be a nightmare on large buildings and happily they are rarely used now.
However on a small garage roof you have on eor two options.
One is to turn it into an artifical pitched roof by fitting new spars across with firring pieces to give a pitch and then recovering. However that's an expensive job so as you ask are the resin based coatings succesful.
I have seen them done succesfully but this was by specialist contractors who used on which had a silver reflective finish.
This has the advantage of reflecting heat instead of it melting the adhesive.
Another is to use green mineral felt which is far stronger and has a kind of carborundum finish to it. Normally the sealing of this would be done with hot poured pitch rather than out of a can but I imagine there are good cold adhesives.
Ordinary roofing felt is normally only suitable for the underside of roof tiles and not for waterproofing of a building.
Worth remembering that snow is an enemy of flat roofs. As it begins to melt the joints have to be perfect as the water can't run off.
Worth having a word with a local roofing contractor as he will be working on these kinds of problems constantly.
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Roofing felt needs to be three layer to be effective, and also to have a perfect substrate to prevent pooling. It is the cheapest way to waterproof a flat roof. Flat roofs have a bad reputation fron the mistakes of the sixties, but modern single ply membranes such as SARNAFIL are very good. I have used them on Further Education college projects exceeding £3million in value, intended to last 40 years.
Agreed as above, the steeper pitch you have the less problems you will risk.
If its any reassurance, I'm an Architect, dontcha know :)
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Mal, Seek a reputable contractor, preferably an approved contractor, approved that is by the felt manufacturer. DO NOT employ some irk with a 2 line ad in the local freebie. Polyester (untearable) felt is fine and should be guaranteed 20 years and is likely to be backed by the manufacturer. I dont know where you live but pay about £20 - £22 per square metre, poss a bit more if you are in one of our lovely big city's!
Regards.
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Mal, Sorry, I forgot to say that the substrate, i.e. the boards under really need to be 18mm sheathing ply. If the original is chipboard, even if it is in good condition REPLACE IT. £15 + VAT and no more for a 2.4m x 1.2 m sheet. Good luck.
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Mal - you haven't said how badly the roof is leaking and what overall state it is in. If there are small holes or sections which are leaking you could tyry soemthing like Coltogum which is a special compound for sealing roofs, damaged pipes etc. I(t can be applied in the wet and remains flexible after it has cured. Webbing is supplied to bridge gaps/holes etc. IIRC a tin costs about £20 and covers several sq metres. It is guaranteed for more than 5 years I believe but you should check exactly how long, Obviously a new roof would be best but given the cost and not knowinbg the extent of the damage or the importance of the garage to you, it may not be worth all that money. At £20 a tin you could try it on part of the roof and see how it works. The only place I have seen it used and demonstrated is QVC on TV - Harry Green reckons you can do an average porch roof with one ! All their products have a 30 day no quibble guarantee so if you tried it, found you didn't like it you could return what's left in the tin and get your money back so there's no risk either. I've used QVC many times for DIY stuff and they've never let me down. Their guarantee is excellent !!
Try ringing their customer services on 0800 514131 for more info.
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Just a test, have tried twice to reply but when I click on post it asks me to log in again and then find I have lost what I have written, does the system log you out after a certain length of time, am I taking too long to write, it is so b...dy annoying.
Mal.
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Martin,Volvoman,
I must confess it is not for my garage.
I live in a single storey cottage which has a flat roof extension to the rear part or which will remain after a roof/loft conversion I am having done.
The problem is common with garage roofs so there is my qualifying slight connection for this thread.
Yes the substrate is chipboard the type which has black felt on one side (this should also be banned).The orriginal being replaced 15 years ago an refelted by what I thought was a reputable contractor much to my cost as I only discovered 2 years ago that he had laid 2 layers of felt not 3!.
I am having a builder in to do this work, I have done all previous building work myself but have to admit defeat with this project and it is he who has suggested a product called "pollyroof" but I am not convinced yet,I am even considering lead sheeting so any thoughts on that
Regards Mal.
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success at last!!!!!!!
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Mal,
See Mark's post 'how to stop losing long replies' in the 'Announcements' section.
HF
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Mal, if you do ever think you'll replace with a pitched roof don't underestimate the magnitude (however you measure it) of the job. I thought I'd replace mine (30 m2) and increase the height of the access and get floored storage in the loft. Having suffered most bad builders in the county, I decided to do it by the book. The builder and most of the tradesmen were OK but the weather wasn't. The garage has a cavity wall (good) but the inner leaf had to be brought up and then plastered (bad, then the job had to be plastered with Alpine finish to match the house (bad). We crunched through cement/concrete from October till December and providentially didn't lose the electricity or central heating which had to be covered over from the elements. As I write this, I'm waiting for the sectional door installer to favour me with his company today and fix the thing for good. I've told them that if isn't working properly by the end of the month I want my money back and they can keep their door. What is wrong with this country where they build houses like this? I can't imagine this job taking more than a fortnight in the US.
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You can always trust a builder selected from the Yellow pages. Try one of these.
www.viz.co.uk/joyofsexism/yellowpages/yell1.html
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Lesson one - do not buy a house with a flat roof anywhere.
Lesson two - do not add on anything with a flat roof.
End of lesson.
Brian
Still learning (I hope)
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Lesson one - do not buy a house with a flat roof anywhere. Lesson two - do not add on anything with a flat roof. End of lesson. Brian Still learning (I hope)
Agree totally flat roofs are trouble from the word go
-always have been
-always will be
-and a good source of income for roofers
chris
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Mal, Your thoughts on covering it in sheet lead.
Origionally being a plumber the answer to that is yes it is excellent for flat roofs but impractical for you to do it. This is specialist skilled work and not easily carried out by the DIY man.
It has to be jointed and the normal method is either lead burning which is welding or by using roll joints with double lock welts. These are not tasks to be embarked upon without experience.
As Brian and others have said flat roofs are a disaster waiting to happen and should be avoided at all costs.
My last 20 years of working life were as a Principal Home Office site Engineer and some of this work was trying to rectify flat roof buildings. Interesting to hear Rob as an architect is working on further education flat roof buildings with 40 year warranties. I would be amazed Rob if they aren?t leaking within 20 years as similar promises were being made in the sixties.
They proved a disaster for us and the worst part was that when they leaked on a large building was finding where the actual water ingress was taking place as it could be tracking along pipes or spars and without taking ceilings down often couldn?t be found.
I would go along with Martins suggestion and employ an approved and reputable roofing contractor who is likely to be around in the future to back up his warranty.
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Well,I am a time served welder with a lot of experience in the oil industry and there is not one metal I have not been able to weld yet so I might look into using lead.
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Actually, companies such as Sarnafil offer a maximum of twenty years warranty, but the buildings themselves are expected to last forty years and longer.
Don't forget that flat roof material companies have a lot to make up for (as all listed above) from previous history so their products have to be A1 watertight, pardon the pun. I'll let you know in forty years time if everything is still OK.
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