Request for advice redoing the deck around fiberglass pool

[keithw]

First thanks to all on this site for help throughout the years. I have a fiberglass pool that I installed myself and got alot of info from this site during the build.

My pool has a raised concrete deck around 3/4 of it.. The deck is pretty solid and has been down for 5-6 years. It terminates about 1/4" below the rim of the pool and angles down into yard. I was looking to improve the look of the pool and really like flagstone and cantilevered edges. I have a quarry nearby where I can get it and was thinking about doing a cantilevered flagstone deck that would extend over the lip of the pool by about 1-2". Originally I was thinking that I would just pry up each of of the concrete pads that I poured around the pool, and pour new pads flush with the pool and flagstone over them. But after reflection, it seem a waste to destroy/remove the pads there already just to pour new ones. So I have questions:

A. Can I mortar down flagstone over the existing pads without removing them? They are currently textured concrete (cobblestone pattern) painted with a Xylene based cement paint. Would they need to be treated to have the mortar stick to them?

B. I might have to raise some portions of the existing deck before applying flagstone. Can I pour a thin layer of some type of special cement mix over the existing deck too work from? Should I just do this to the whole deck to make it consistent? If I can do this, what special mortar would I use? Any special prep?

C. How would one prep the lip of the pool to adhere better to the flagstone. I was thinking drill holes in the lip, sand it down, and comb epoxy over it to give it texture. After the flagstone is on should I caulk underneath the lip where the flagstone meets the fiberglass?

D. Other other advice?

Here is a link for my build that show how the deck looks now. I am planning to build a cinder block frame around the side that is currently wood decking and then filling it with compacted road base and them doing the flagstone over that. Here some pics as well


Current deck. It might look like individual stones but it is solid with a patten pressed into it.

Here is the look that I am going for:

 

[PoolGuyNJ]

Re: Request for advice redoing the deck around fiberglass po

I didn't like the answer I saw you got on the G/W forum. IMHO, the right way to do what you want is to remove the existing decking.

I don't know if you put j hooked rebar in the coping when you poured this one though. That will make demo easier if you didn't. You will need it for a replacement deck though and it will need to be attached to the bonding grid in at least four places. Use #3 rebar pieces, the length of which should be four to six inches less than the desired width of the deck, placed in holes drilled every 18" around the perimeter.

Wire tie additional rebar to form a grid and set dobies (blocks) under the grid to lift it a couple inches.

Attach canter lever forms to the top of the pool coping. Attach an extension collar to the skimmer. You probably destroyed the old one when you did the demo.

Pour your concrete. The rebar and bond wire will be embedded in the concrete. You want a sub deck at least three inch thick over the pool rim. The top of the coping and the bottom of the cement will expand at different rates. Eventually, a bead of silicon will be needed to keep moisture out.

The rebar will lock the pool and concrete providing an additional weight to hold the pool down should you need to lower the pool.

Make sure the final height over the pool shell is at least three and half inches and use saw cuts for expansion joints, shallow need the pool edge and gradually deepening as you move out. Leave about a 1/2" uncut at the pool edge so dirt can't flow back in from splash out and rain.

Your final height when the sub-deck, mortar and stones are added will be about five inches over the fiberglass rim. The stones will need to be set in mortar and grouted. This should be done while the initial pour is still green to improve the bond between the mortar and poured sub-deck.

When choosing your stone, harder is better. A basic test is to scratch it with a screwdriver. If the scratch is white, it's too soft a material, find another material.

Scott

 

[keithw]

Re: Request for advice redoing the deck around fiberglass po

Scott,

Thanks for the advice. That is exactly what I needed.

 

[dantan]

Re: Request for advice redoing the deck around fiberglass po

I'd love to see the finished deck if you have pics (even better if you took pics while you were doing the work)! I'm about to start the same project on a new pool install. Scott's guidance above is great, but I really don't want 5+ inches above my pool wall... there are folks in my neighborhood that have done it with just the thickness of the flagstone over the wall... I assume there is a concrete base (over a compacted gravel sub-base) that comes up to the same height of the pool and then the flagstone is mortared to the concrete and (potentially) the fiberglass shell, but it might not be... maybe adhesive of some sort on that part of the stone.