GRP roof topcoat wet and coming off at the touch

[Krad]

Hi I had a GRP roof done last week and the builder put the topcoat in the evening and the day before we had rain so I think the laminate/resin was wet on the roof (when he applied topcoat).
Today I checked the roof and the topcoat is wet, some area with ridge and coming off when I touch it. When I press with the hand, the print remains on the roof.

The builder said it's not a problem and there is no leak. I found online that if the topcoat is wet then it's better to sand it off and reapply the mat and resin to make sure no damage to laminate and then put the topcoat again.

Do I need to get the GRP done from scratch? Or is there another solution?

Thank you

 

[noseall]

Hi I had a GRP roof done last week and the builder put the topcoat in the evening and the day before we had rain so I think the laminate/resin was wet on the roof (when he applied topcoat).
Today I checked the roof and the topcoat is wet, some area with ridge and coming off when I touch it. When I press with the hand, the print remains on the roof.

The builder said it's not a problem and there is no leak. I found online that if the topcoat is wet then it's better to sand it off and reapply the mat and resin to make sure no damage to laminate and then put the topcoat again.

Do I need to get the GRP done from scratch? Or is there another solution?

Thank you

What's going on with that bonkers gap by the wall? It can't be where the water runs off, surely?

 

[catlad]

Who would do that at this time of year!

 

[Krad]

What's going on with that bonkers gap by the wall? It can't be where the water runs off, surely?

Yes that's where the builder puts the guttering for the water to run off. This is the picture of the guttering. Hope that's okay as I don't want another headache

 

[noseall]

Yes that's where the builder puts the guttering for the water to run off. This is the picture of the guttering. Hope that's okay as I don't want another headache

WTF!

 

[freddiemercurystwin]

Wow!

 

[ree]

OP,
As above, there's a few things wrong with the GRP, the flashing & the gutter.
There's a guy called "fixmyroof" on you tube - at least you would get a good example from his GRP video?

Whatever, check out your neighbour's pitched roof?

 

[Rufus Raintight]

if the topcoat has been on the roof for nearly a week and it hasn’t cured then that’s definitely not right and your builder needs to come back and fix the issue despite him saying it’s not leaking.

He would need to remove the uncured areas, abrade the area, acetone wash and reapply onto a dry surface.

Do you know what system they used?

 

[Krad]

OP,
As above, there's a few things wrong with the GRP, the flashing & the gutter.
There's a guy called "fixmyroof" on you tube - at least you would get a good example from his GRP video?

Whatever, check out your neighbour's pitched roof?

Ok thank you for the youtube channel, I'll check it out. The builder installed wall trims (and then covered it with lead flashing, not sure why) and the gutter trim on the gutter side to allow the water to flow down to the gutter.

 

[Krad]

if the topcoat has been on the roof for nearly a week and it hasn’t cured then that’s definitely not right and your builder needs to come back and fix the issue despite him saying it’s not leaking.

He would need to remove the uncured areas, abrade the area, acetone wash and reapply onto a dry surface.

Do you know what system they used?

Ok thank you, I'll ask the builder to come and have a look and do the job on a dry day to avoid the same issue. Does acetone affect/damage the laminate/resin integrity? As the laminate is fine and no leak.

Sorry but I'm not sure what you mean with system. If you mean the products then all GRP products from Cromar Pro GRP (Matt roll, trims, resin and topcoat)

One thing I noticed is that the builder mixed the hardener directly into the 20kg bucket (not sure if he used any ratio calculation), even though the product is already a pre accelerated formula. Is it possible that the hardener affected the final result?

 

[Rufus Raintight]

One thing I noticed is that the builder mixed the hardener directly into the 20kg bucket (not sure if he used any ratio calculation), even though the product is already a pre accelerated formula. Is it possible that the hardener affected the final result?

Well you definitely, definitely don’t do that. You need to make topcoat up in batches, having an exact qty of catalyst going into an exact amount of topcoat for it to cure correctly. This might explain why you have patches of liquid topcoat on the roof.

Drag your builder back by the nostrils and get him to apply it correctly, this is totally unacceptable!