fibreglass balcony problem

[petronius]

I have a balcony (approx. 4000 x 1500 mm) that a few years ago has been fibreglassed and tiled over. It looked OK at the beginning, but I soon realised they had done a really poor job and I am now dealing with the consequences.

The first problem is that they did not use the right adhesive for fibreglass (just normal tile adhesive, I guess) and the tiles are coming loose.

Another problem is that they did not create a good slope, so rain water does not drain properly.

Finally, the topcoat is detaching from the fibreglass - I don't think they used the right material.

My plan is to remove the tiles, sand off as much of the top coat as I can and apply a new white topcoat (without tiles if I can get an acceptable finish).

If at all possible, I'd also like to create the slope that is now missing to have proper drainage. I have no idea if this is possible at this stage though, without removing the fibreglass and reposition the boards underneath. Can I somehow achieve this by placing more fibreglass on top of the existing one?

Any advice on whether this plan is feasible and about the best way to do things would be gratefully received! I have decent DIY skills but have never dealt with fibreglass. Chasing the cowboy builders is not an option, I considered suing them but decided not to.

[tjh290633]

This sounds a bit odd. How was the glass fibre applied?

Was it hand layup GRP, or was it prefabricated? If it is on top of boards, to get a slope you are going to have to start with the boards, I would have thought, or have a drain point.

As the Irishman said, if it were me, I wouldn't be starting from here.

TJH

[bungeejumper]

Boards? You mean that the fibreglass was laid over an exterior-quality wooden surface that was somehow failing? As suggested, that's where you'd presumably have to start.

On the principle that you should always ask the stupid questions, is this a house or a flat, and how many storeys up are you? (Might determine your options if, as I suspect, the lack of a drain was what caused the original problem.)

WRT fibreglass, it needs careful handling if you're sanding. The dust isn't particularly nice. Is there perhaps a rubberised floor paint surface that would be better than tiles?

BJ

[Mike88]

Having a decent slope on a fibreglas roof is not that essential. After all the surface is like a boat and should be waterproof. Could you not re apply the tiles with the correct adhesive. I used this on my fibreglas roof which is suitable for composite type tiles but its use must depend on the type of tiles used.

https://www.castlecomposites.co.uk/prod ... -adhesive/

[petronius]

They attached chipboards on joists and then put fibreglass sheets over the board soaked with clear liquid resin.

Not sure about the type of chipboard, but they were new.

There are some vertical timber posts (used to hold glass panels), so they applied the resin around them creating sort of pyramid shapes around the posts. One of them started leaking, so as a temporary emergency measure I put silicon caulk to stop water ingress.

It is a house and this is the top floor, so there is nothing above it.

[petronius]

Could you not re apply the tiles with the correct adhesive.

I could do this, but the top coat is failing, so I need to fix that first. Once I manage to have a decent solid surface, I may opt for tiles again. Thanks for the link to the product, it sounds like the right material for the job.

[tjh290633]

They attached chipboards on joists and then put fibreglass sheets over the board soaked with clear liquid resin.

Not sure about the type of chipboard, but they were new.

There are some vertical timber posts (used to hold glass panels), so they applied the resin around them creating sort of pyramid shapes around the posts. One of them started leaking, so as a temporary emergency measure I put silicon caulk to stop water ingress.

It is a house and this is the top floor, so there is nothing above it.

Was the glass fibre in the form of chopped strand mat and the resin applied after it was laid? Usually, if you are laying up a mould by hand, there is a gel coat which forms the final surface. Not possible if it was just hand laid on top of chipboard.

It sounds a very odd way of doing the job to me. How did they achieve the final surface finish?

TJH

[petronius]

The procedure they used was similar to that described in this video:

https://www.youtube.com/watch?v=A4p8TpzFcWQ

Resin spread over a fibreglass matt. All this on top of chipboards.

[Mike88]

The procedure they used was similar to that described in this video:

https://www.youtube.com/watch?v=A4p8TpzFcWQ

Resin spread over a fibreglass matt. All this on top of chipboards.

Shouldn't really use chipboard as it decomposes. Plywood is far better.

[bungeejumper]

Shouldn't really use chipboard as it decomposes. Plywood is far better.

To misquote Hermann Goering, every time I hear the word chipboard I reach for my revolver.

And to think, they build houses with the stuff....

BJ

(In case you're wondering, Goering's allergy was toward "culture".)

[bionichamster]

Doesn’t sound great, although maybe not unsalvageable, however it may be less hassle to completley redo it.

My first thought, is chipboard? Outdoors??
Second thought: so the fibreglass has holes in it with bits of wood poking through?
That’s a combination that’s never going to end well.

I would have expected them to leave the fibreglass and resin with a flat but rough finish, not sure about painting it with anything so long as the resin is waterproof. with a rough finish surely the tile adhesive would get a good grip? As an example the only reason I’d paint a wall before putting tiles on it would be so they are easier to pull off when Mrs BH decides that she no longer likes them, I’m not sure I’d want to risk the same effect outside on a floor.

A slope on the floor might be achieved with an extra sheet(s) of fibreglass resined on at the back to raise it slightly, although you might just manage it by careful laying of tiles and varying the tile adhesive thickness very slightly back to front. Guess it depends on the distance involved.

But it’s the wood poking through that would concern me, surely that should at the very least be a metal pin or bracket onto which the wood is mounted? Better still a metal plate (quality stainless steel) set in the fibreglass and into which a metal attachment is screwed/bolted and then wood fitted? And at the end of the day the best solution would be a balustrade system that sat on top without breaking the surface, perhaps attached to the walls.

I would recommend calling a few balustrade manufacturers to see what they recommend for a fibreglass floor, then decide how to proceed. If it were me I’d probably patch it up to look reasonable and start saving to redo it properly.

You may find this thread of interest: https://forum.buildhub.org.uk/topic/145 ... r-balcony/

Weirdly the guy seems to think that setting a block of wood in the fibreglass is standard practice, sounds distinctly cowboy to me, no idea why it wouldn’t be a stainless steel plate, but there you go! But a few alternatives are offered.

BH

[sg31]

Doesn’t sound great, although maybe not unsalvageable, however it may be less hassle to completley redo it.

My first thought, is chipboard? Outdoors??
Second thought: so the fibreglass has holes in it with bits of wood poking through?
That’s a combination that’s never going to end well.

I would have expected them to leave the fibreglass and resin with a flat but rough finish, not sure about painting it with anything so long as the resin is waterproof. with a rough finish surely the tile adhesive would get a good grip? As an example the only reason I’d paint a wall before putting tiles on it would be so they are easier to pull off when Mrs BH decides that she no longer likes them, I’m not sure I’d want to risk the same effect outside on a floor.

A slope on the floor might be achieved with an extra sheet(s) of fibreglass resined on at the back to raise it slightly, although you might just manage it by careful laying of tiles and varying the tile adhesive thickness very slightly back to front. Guess it depends on the distance involved.

But it’s the wood poking through that would concern me, surely that should at the very least be a metal pin or bracket onto which the wood is mounted? Better still a metal plate (quality stainless steel) set in the fibreglass and into which a metal attachment is screwed/bolted and then wood fitted? And at the end of the day the best solution would be a balustrade system that sat on top without breaking the surface, perhaps attached to the walls.

I would recommend calling a few balustrade manufacturers to see what they recommend for a fibreglass floor, then decide how to proceed. If it were me I’d probably patch it up to look reasonable and start saving to redo it properly.

You may find this thread of interest: https://forum.buildhub.org.uk/topic/145 ... r-balcony/

Weirdly the guy seems to think that setting a block of wood in the fibreglass is standard practice, sounds distinctly cowboy to me, no idea why it wouldn’t be a stainless steel plate, but there you go! But a few alternatives are offered.

BH

I'm a retired builder but have never done a fibreglass roof. I was also a fibreglass boat owner and did a lot of work on it so I have some knowledge of fibreglass work. In addition I've just had my garage roof redone on fibreglass and watched the process.

Chipboadrd is totally unsuitable for the roof boards,OSB board would be much better option preferrably T & G or the joints need covering with fibreglass tape and resin. Usual practice is to apply resin to the roof with a roller then apply the glass matting and then roller more resin over the top until it fully saturates the mat. the roof is at that stage waterproof but it still needs a coat of gell coat to finish it so that it looks better and is UV proof to stop deterioration of the glass fibre and resin.

I'm no expert but the above gives a general idea of the process.

[bionichamster]

I'm a retired builder but have never done a fibreglass roof. I was also a fibreglass boat owner and did a lot of work on it so I have some knowledge of fibreglass work. In addition I've just had my garage roof redone on fibreglass and watched the process.

Chipboadrd is totally unsuitable for the roof boards,OSB board would be much better option preferrably T & G or the joints need covering with fibreglass tape and resin. Usual practice is to apply resin to the roof with a roller then apply the glass matting and then roller more resin over the top until it fully saturates the mat. the roof is at that stage waterproof but it still needs a coat of gell coat to finish it so that it looks better and is UV proof to stop deterioration of the glass fibre and resin.

I'm no expert but the above gives a general idea of the process.

I appreciate the use of a gel coat for the finish on boats and cars, especially straight from the mould , but do you think it would be necessary if the next stage was laying tiles on top with tile adhesive? Obviously if the basic resin and fibreglass layer is capable of absorbing moisture then there is a case for it, if not, and the basic layer is stable it seems superfluous. And even with a gel coat I'm pretty sure I wouldn't paint it prior to tiling.

ALthough I'm no expert either, but interested to know how far the described installation deviates from acceptable practice. I have 'flat' roof extension that will need reflecting in a few years and may opt to change the roof to epdm or maybe fibreglass if they look like better options.

BH

[sg31]

I appreciate the use of a gel coat for the finish on boats and cars, especially straight from the mould , but do you think it would be necessary if the next stage was laying tiles on top with tile adhesive? Obviously if the basic resin and fibreglass layer is capable of absorbing moisture then there is a case for it, if not, and the basic layer is stable it seems superfluous. And even with a gel coat I'm pretty sure I wouldn't paint it prior to tiling.

ALthough I'm no expert either, but interested to know how far the described installation deviates from acceptable practice. I have 'flat' roof extension that will need reflecting in a few years and may opt to change the roof to epdm or maybe fibreglass if they look like better options.

BH

I've no idea id the gel coat is essential under tiles but personally I'd use it anyway. The cost of materials wouldn't be outrageous and it's quick to apply. If I was going to tile I'd spread sand on top of the gel coat to act as a key. I know this is done with boat decks to provide a non slip surface.

I think the other reason to use the gel coat is to make everything not tiled uniforn. The edge trims and glass fibre impregnated mat will be diiferent colours until gel coat is applied.

I've never done a glass fibre roof or seen one tiled over so I'm not saying I know the answer definitively.

[Mike88]

I appreciate the use of a gel coat for the finish on boats and cars, especially straight from the mould , but do you think it would be necessary if the next stage was laying tiles on top with tile adhesive? Obviously if the basic resin and fibreglass layer is capable of absorbing moisture then there is a case for it, if not, and the basic layer is stable it seems superfluous. And even with a gel coat I'm pretty sure I wouldn't paint it prior to tiling.

ALthough I'm no expert either, but interested to know how far the described installation deviates from acceptable practice. I have 'flat' roof extension that will need reflecting in a few years and may opt to change the roof to epdm or maybe fibreglass if they look like better options.

BH

I've no idea id the gel coat is essential under tiles but personally I'd use it anyway. The cost of materials wouldn't be outrageous and it's quick to apply. If I was going to tile I'd spread sand on top of the gel coat to act as a key. I know this is done with boat decks to provide a non slip surface.

I think the other reason to use the gel coat is to make everything not tiled uniforn. The edge trims and glass fibre impregnated mat will be diferent colours until gel coat is applied.

I've never done a glass fibre roof or seen one tiled over so I'm not saying I know the answer definitively.

Spreading sand on top of the gel coat is not a good idea but it all depends on the type of adhesive used. The adhesive I referred to in my earlier post is designed to let water run underneath it and if of a type mainly used for composite/promenade tiles such as these:

https://www.castlecomposites.co.uk/prod ... ade-tiles/

I can't imagine using sand with a more conventional tile adhesive either as a clean surface is required.