Replacing pool light niche

[marcperrys]

Hi there
Does anybody have any experience in replacing a metal niche for a pool light. This ones in an in ground fiber glass pool. The existing one has been repaired 3 times and now needs swapping out as leaking yet again. Any views on this would be much appreciated
Thanks

 

[ajw22]

Welcome to TFP.

I think you will need to dig down the back of the pool to get to the niche.

Details on the niche and pics of the situation may get more ideas.

@Texas Splash thoughts?

 

[Texas Splash]

Hey Marc, and welcome! It would definitely help readers to know what type of light fixture we're talking about (traditional halogen, LED, large, small, etc). A pic or two may help. Can you explain what repair techniques were done in the past? Epoxy around the rear conduit entrance perhaps?

If you believe the entire wet niche needs to be replaced, one of the biggest concerns I see would be the lower water level required. Not sure about the water table in your area, but I suspect you would need to drop about 2-3 feet of water right? That leaves the potential for the shell to shift/pop-up which you want to avoid, so I'd look into that before proceeding. That fear alone could take this job outside of the typical "DIY" concept. FG pool companies in your area should be familiar with niche-replacing and any tasks required to brace your pool prior to excessive water removal. Bracing may be required from side-to-side, and in some cases even drill relief holes at the bottom to relieve upwards pressure, then it gets sealed/coated later.

Once the pool is secure and water lowered, it should be a matter of digging down to gain access the niche to remove the old niche and replace with the new one. There are a variety of replacement products nowadays, so the process could vary a bit depending on the vendor doing the work. I would suspect anyone installing a replacement niche would ensure the new one would mate-up properly to the existing hole in the shell, or at the very least minimize gelcoat repair around the effected area (if needed).

While not FG-specific, the following video below give a good illustration of sorts to common niche leaking situations.

 

[marcperrys]

Thanks for the welcome guys!!
Pic of the exact replacement niche and light fitting below. Haven’t taken a picture of the pool but I can tell you that it has been drained already to just above the light fitting so really needs a bit more water out before I can work on the niche. Repair to the existing niche has been done 3 times with epoxy around the cable entry and the customer is sick of the issue and wants a complete replacement so having a worry free solution. Digging behind the light would be an absolute nightmare but not impossible. A good 3/4 foot down with 4/5 foot of pool deck to overcome too! Thinking of ways to do this from the pool side so not to have to dig out.

 

[Texas Splash]

Thinking of ways to do this from the pool side so not to have to dig out.

So I was looking into this Pentair Manual which got me thinking:

FG niches are originally installed from the inside, but then you're left with the conduit on the back-side attached during the original install. So in this case I wondered .... once the original niche was unfastened from the shell (from inside the pool), would there be some play in that conduit behind the pool? Enough to allow the old niche to slide out (into the pool) just a few inches to work with?

If that were true, could you manage to remove the old niche. Maybe cut the niche shell itself, pry it apart, and separate it from the conduit line, knowing at some point you would have to clean and reattach a conduit line back to the new niche? Keep in mind I'm not aware of any techniques designed to do all this from inside the pool, so this is just some "what-if" scenario. But if you got the old niche removed, could you bore (tunnel) a hole through the soil from the niche opening while in the pool, backwards & away from the pool to where you might get to a point where you could get to it easier from above ground without having to go under the decking? If that were possible, then you could attach a new conduit line (few feet) to the new niche and feed it out through that new tunnel created. Then you only have to dig down - work from that point behind the decking to connect the conduit line and feed the light wire? Thought it may save you from having to go under the decking anyways.

Yeah, maybe this is just wishful thinking, .... a pipe dream, but it's my small brainstorm. I'm not in the trenches like you in the industry, but if nothing else, I figured I'd toss it out there in case any of it seems feasible for your situation. Ideally, sure .... dig down and under the decking to gain access to the shell directly behind. You may end-up doing that anyways, but if my rambling doesn't give you any ideas, maybe someone else will have a thought or two.

Hope it all works out for you. Let us know how you end-up tacking it.

 

[marcperrys]

So I was looking into this Pentair Manual which got me thinking:

FG niches are originally installed from the inside, but then you're left with the conduit on the back-side attached during the original install. So in this case I wondered .... once the original niche was unfastened from the shell (from inside the pool), would there be some play in that conduit behind the pool? Enough to allow the old niche to slide out (into the pool) just a few inches to work with?

If that were true, could you manage to remove the old niche. Maybe cut the niche shell itself, pry it apart, and separate it from the conduit line, knowing at some point you would have to clean and reattach a conduit line back to the new niche? Keep in mind I'm not aware of any techniques designed to do all this from inside the pool, so this is just some "what-if" scenario. But if you got the old niche removed, could you bore (tunnel) a hole through the soil from the niche opening while in the pool, backwards & away from the pool to where you might get to a point where you could get to it easier from above ground without having to go under the decking? If that were possible, then you could attach a new conduit line (few feet) to the new niche and feed it out through that new tunnel created. Then you only have to dig down - work from that point behind the decking to connect the conduit line and feed the light wire? Thought it may save you from having to go under the decking anyways.

Yeah, maybe this is just wishful thinking, .... a pipe dream, but it's my small brainstorm. I'm not in the trenches like you in the industry, but if nothing else, I figured I'd toss it out there in case any of it seems feasible for your situation. Ideally, sure .... dig down and under the decking to gain access to the shell directly behind. You may end-up doing that anyways, but if my rambling doesn't give you any ideas, maybe someone else will have a thought or two.

Hope it all works out for you. Let us know how you end-up tacking it.

 

[marcperrys]

Hitting this job Sat morning one of those get stuck in and see how it pans out jobs. Thinking that I’m going to need to stitch drill round the old niche conduit entry to release it and adapt the conduit fitting to the new niche outlet somehow! Will let you know. Appreciate the input.

 

[marcperrys]

So I was looking into this Pentair Manual which got me thinking:

FG niches are originally installed from the inside, but then you're left with the conduit on the back-side attached during the original install. So in this case I wondered .... once the original niche was unfastened from the shell (from inside the pool), would there be some play in that conduit behind the pool? Enough to allow the old niche to slide out (into the pool) just a few inches to work with?

If that were true, could you manage to remove the old niche. Maybe cut the niche shell itself, pry it apart, and separate it from the conduit line, knowing at some point you would have to clean and reattach a conduit line back to the new niche? Keep in mind I'm not aware of any techniques designed to do all this from inside the pool, so this is just some "what-if" scenario. But if you got the old niche removed, could you bore (tunnel) a hole through the soil from the niche opening while in the pool, backwards & away from the pool to where you might get to a point where you could get to it easier from above ground without having to go under the decking? If that were possible, then you could attach a new conduit line (few feet) to the new niche and feed it out through that new tunnel created. Then you only have to dig down - work from that point behind the decking to connect the conduit line and feed the light wire? Thought it may save you from having to go under the decking anyways.

Yeah, maybe this is just wishful thinking, .... a pipe dream, but it's my small brainstorm. I'm not in the trenches like you in the industry, but if nothing else, I figured I'd toss it out there in case any of it seems feasible for your situation. Ideally, sure .... dig down and under the decking to gain access to the shell directly behind. You may end-up doing that anyways, but if my rambling doesn't give you any ideas, maybe someone else will have a thought or two.

Hope it all works out for you. Let us know how you end-up tacking it.

well not the way it should be done but achieved without digging a trench from behind. The old niche was easier than expected to remove. Drained the pool first which wasn’t too much as the leak had done that job for me then chiseled off the old poor epoxy joint. Removed 6 screws then had to pryit out with a chisel and claw hammer. The existing conduit wasn’t even clamped/screwed in just epoxy rammed in the back Conduit. So out came the niche. Dug out a fair bit of sand and dirt from around the conduit to see if I could get any play. Managed to get enough just to move the conduit to one side of the niche as fixing the conduit to new niche not an option as I’d hoped no back and forward movement. Had to use IP68 good quality male compression gland in the back of the new niche which I also filled with JB weld epoxy once the new light cable was pulled in and compression gland tightened. Existing conduit was also filled with epoxy to stop water returning. Used some liquid gasket compound to seal round the edges of the new niche gasket screwed it all back and should have a pool back to holding water with a new light. Drawback of using this method is you have to remove the niche again to replace a light should that need to happen at any stage in the future. Something I don’t want to make a habit of but with all the options relayed to the customer seemed a fair way to proceed! Had the conduit inlet point been centre of the niche I may have been able to spin it onto the thread. Maybe a slight design flaw there as it’s off center. Wouldsave a lot of hassle.

 

[Texas Splash]

Wow. Quite an ordeal. But you got it done. Sounds as if the customer is satisfied, so that's a bonus.