DIY Forum

 

Ultimate Handyman Ultimate Handyman Ultimate Handyman Ultimate HandymanUltimate Handyman on Pinterest

 

DIY Forum/Home improvement advice forum

 

 

A-Z CONTENTS | DISCLAIMER | DIY VIDEO | HOME | SAFETY FIRST | FORUM RULES

It is currently Mon Oct 16, 2017 11:11 pm
Visit Thermo worx


Time zone: Europe/London [ DST ]




 

 


Post new topic Reply to topic  [ 10 posts ] 
Author Message
 Post subject: Flat Roofs: EDPM vs GRP
PostPosted: Sat May 20, 2017 2:59 pm 
Offline
Senior Member

Joined: Sat Feb 14, 2009 5:24 pm
Posts: 162
Has thanked: 4 times
Been thanked: 5 times
I want the flat roofs complete replacing on a property I own:

Image

Currently they are old felt / bitumen. The ceiling roof has leaked into the lounge every year for the past 14 years I've owned it. I estimate the current roofs are more than 30 to 40 years old. The management company's contractors are only doing a cheap patch repair.

Please advise on the suitability of EDPM or GRP. I'm trying to understand the advantages and disadvantages of each material.

Many thanks!


Share on FacebookShare on TwitterShare on DiggShare on DeliciousShare on Google+
Top
 Profile  
Reply with quote  
PostPosted: Sat May 20, 2017 4:11 pm 
Offline
Senior Member
User avatar

Joined: Fri Feb 26, 2010 11:16 am
Posts: 1606
Location: Camberley Surrey
Has thanked: 90 times
Been thanked: 266 times
I have white GRP over the bays on my old house, every few years I 2 part paint, as used on boat hulls, if black is okay then EDPM or a good quality thick felt should work out cheaper.


Top
 Profile  
Reply with quote  
PostPosted: Wed May 24, 2017 9:18 pm 
Offline
Senior Member

Joined: Sat Feb 14, 2009 5:24 pm
Posts: 162
Has thanked: 4 times
Been thanked: 5 times
I've been quoted £1300 by a roofing contract to install GRP on both roofs. Sounds reasonable?


Top
 Profile  
Reply with quote  
PostPosted: Wed May 24, 2017 10:24 pm 
Offline
Senior Member
User avatar

Joined: Thu Mar 09, 2017 4:47 pm
Posts: 531
Location: East Riding of Yorkshire
Has thanked: 11 times
Been thanked: 150 times
Distorted Vision wrote:
I've been quoted £1300 by a roofing contract to install GRP on both roofs. Sounds reasonable?


See what period of guarantee he is prepared to give you; it should be 20 years.

davyp1


Top
 Profile  
Reply with quote  
PostPosted: Wed May 24, 2017 10:27 pm 
Offline
Senior Member

Joined: Sat Feb 14, 2009 5:24 pm
Posts: 162
Has thanked: 4 times
Been thanked: 5 times
Yes it is 20 years.


Top
 Profile  
Reply with quote  
PostPosted: Thu May 25, 2017 7:31 am 
Offline
Senior Member
User avatar

Joined: Thu Mar 09, 2017 4:47 pm
Posts: 531
Location: East Riding of Yorkshire
Has thanked: 11 times
Been thanked: 150 times
As I understand it, this guarantee is backed by the suppliers/manufacturers of the GRP materials to the roofers. I'm also given to understand that their is also a proviso that OSB Tongue and grooved boards are used to support the GRP.
If their quote includes the above, also for insulation bringing it up to current regs, I do think the quote resonable. But you could also get a check quote.

davyp1


Top
 Profile  
Reply with quote  
PostPosted: Thu May 25, 2017 9:18 am 
Offline
Senior Member

Joined: Fri Oct 16, 2015 7:20 pm
Posts: 319
Has thanked: 2 times
Been thanked: 83 times
We use GRP for orangery roofs.

The great advantage of GRP is that it is formed wet on site to any shape required, so for us any awkward gullys, house abutments, hopper shoots can all be fibreglassed and when finished there are effectively no joints anywhere.

The disadvantage of fibreglass is that it is very rigid so must be fitted that allow any movement and expansion / contraction on the structure. For an orangery that means the fibreglass is not stuck to the host building. On the orangery an upstand is fitted and screwed to the orangery roof up against the house wall, the fibreglass is bonded to the upstand then later lead flashing is dressed down over. Any movement that subsequently occurs only means the lead flashing is pulled a bit.

We use GRP with a darkish lead grey colour which seems to suit all situations really well.

Also nothing wrong with EPDM, but I think it is best suited to simple flat roofs which have no awkward nooks and crannies to be formed. The difference between the 2 systems depends more on the quality of the workmanship than the system used.

I tend to pay around £1,500 to £2,000+vat for an orangery roof to be done, which given that is just for fibreglassing and no insulation or timber, I think £1,200 is a fair price.

You might want to ask them about protecting the bay windows from drips etc whilst the work is done, GRP resin is a bugger to get off when its set!
Id be tempted to cover them completely with plastic sheeting.


Top
 Profile  
Reply with quote  
PostPosted: Thu May 25, 2017 9:31 am 
Offline
Senior Member
User avatar

Joined: Thu Mar 09, 2017 4:47 pm
Posts: 531
Location: East Riding of Yorkshire
Has thanked: 11 times
Been thanked: 150 times
Notch1 wrote:
We use GRP for orangery roofs.

The great advantage of GRP is that it is formed wet on site to any shape required, so for us any awkward gullys, house abutments, hopper shoots can all be fibreglassed and when finished there are effectively no joints anywhere.

The disadvantage of fibreglass is that it is very rigid so must be fitted that allow any movement and expansion / contraction on the structure. For an orangery that means the fibreglass is not stuck to the host building. On the orangery an upstand is fitted and screwed to the orangery roof up against the house wall, the fibreglass is bonded to the upstand then later lead flashing is dressed down over. Any movement that subsequently occurs only means the lead flashing is pulled a bit.

We use GRP with a darkish lead grey colour which seems to suit all situations really well.

Also nothing wrong with EPDM, but I think it is best suited to simple flat roofs which have no awkward nooks and crannies to be formed. The difference between the 2 systems depends more on the quality of the workmanship than the system used.

I tend to pay around £1,500 to £2,000+vat for an orangery roof to be done, which given that is just for fibreglassing and no insulation or timber, I think £1,200 is a fair price.

You might want to ask them about protecting the bay windows from drips etc whilst the work is done, GRP resin is a bugger to get off when its set!
Id be tempted to cover them completely with plastic sheeting.



Notch, how about maintenance?
When I last had a roof done (about three years ago now) nothing was mentioned. I just wonder if anyone recommends
repainting say every five years or so?

davyp1


Top
 Profile  
Reply with quote  
PostPosted: Thu May 25, 2017 11:28 am 
Offline
Senior Member
User avatar

Joined: Fri Feb 26, 2010 11:16 am
Posts: 1606
Location: Camberley Surrey
Has thanked: 90 times
Been thanked: 266 times
As said earlier I treat / paint mine like a boat hull as it is South facing and gets sunshine, UV, you have a good price if the product is finished correctly with a good thickness Gelcoat 0.5mm or more, as otherwise it will degrade with UV, mine is 37yrs old.


Top
 Profile  
Reply with quote  
PostPosted: Thu May 25, 2017 4:11 pm 
Offline
Senior Member

Joined: Fri Oct 16, 2015 7:20 pm
Posts: 319
Has thanked: 2 times
Been thanked: 83 times
Hi Davyp1,

I'm not aware any maintenance is required provided the gel coat is sufficiently thick.

I suppose a dark colour could fade as it is an added pigment in the same way pigment is added to paint rather than the self colour of the material. Ive done jobs that must be up to 10 years old and cant say ive ever seen any issues when returning to jobs. Out of interest I will ask the guys that do it and report back, as I would be interested to know.


Top
 Profile  
Reply with quote  
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 10 posts ] 


Similar topics
   

Time zone: Europe/London [ DST ]


Who is online

Users browsing this forum: No registered users and 1 guest


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Visit Hilti


 

 

 

News News Site map Site map SitemapIndex SitemapIndex RSS Feed RSS Feed Channel list Channel list
ultimatehandyman privacy policy

Contact

 

Powered by phpBB® Forum Software © phpBB Group

phpBB SEO