Pool Refurb

[gregch]

Hello folks, haven't posted here in a while, good to be back!

Our pool came with the house and was already very old and a bit dilapidated when we moved in 10 years ago! I believe it's exactly as originally built in 1987 - including the vinyl liner. With some help I've managed to keep it ticking over - water always cleans up and balances perfectly,and patched up but it's finally time for a refurb.

It's an in-ground concrete block and vinyl liner pool. We're going to change the liner, and completely replace the copings and paving around the pool area. (Currently pretty much all the copings are loose, which is a safety concern).

I've got an experienced professional to measure up for, and fit, the liner and a friend's going to help us with the coping and paving. I also want to renew all the visible parts of the skimmer, deck box for the light and so on.

I have a concern about the skimmer in relation to the finished level of the pool 'deck' area. It looks to me like when the pool was built, he didn't dig it deep enough, meaning that the finished coping level is some way about the surrounding area. He's attempted to deal with that by putting in terrazzo slabs at an alarmingly steep angle between the coping stones and surrounding paving (see photo). The deck box of the skimmer consequently sits proud of the sloping terrazzo - and is if anything even slightly above the level of the copings.

Given the paved area surrounding the pool connects to higher ground either side, I'd like to raise the level of the paving closer to the coping. We're also planning to use a concrete coping stone that slopes from 1.75" to 1" (the existing coping is c. 2" and flat) to try and finesse away the difference in level so the surrounding slabs (1" thick) will be exactly level with the outer edge of the coping. Hope you're with me so far!

My concern is that - if the skimmer lid is already at or above the level of the existing coping, how can I get it level with the new coping/paving that's going to be almost 1" lower? My understanding is that the top section of the skimmer box is separate and can move up and down but it doesn't look like there's that much adjustment? I'll attempt to break out around it and have a look, but in the meantime would be great to get some insights/suggestions. It's a Certikin HD100 skimmer, if that means anything (we're in the UK so I'm aware not all the products here are the same).

Thanks!

 

[cowboycasey]

I would just raise the pavings to the same height as the coping and be done with it.. If you keep the coping at normal 2 inch you can raise the stones outside the coping to match the coping

 

[kimkats]

What I keep coming back to is why the first person did what they did...............is it because they had problems with water running from the yard/grass into the pool during heavy rains. So they pushed the pool side of the slabs and coping up a bit to try to keep the water out of the pool?

Skimmer height-when you take the skimmer cover off can you tell if it CAN be moved up or down? How deep is the skimmer? I have an idea but need to see inside the skimmer with a tape measure to know if what I am thinking can works BUT I also need to know if heavy rain will be a problem if you lower the coping and decking.

Kim

 

[gregch]

Well I guess it's possible that the previous owner made a deliberate decision to elevate the pool edge so that stuff didn't wash into the pool. There's certainly some logic to that.

We do plan to raise up the paving a fair bit, so as to match the outer edge of the new copings but we have chosen a coping that has a raised edge against the pool to try to mitigate stuff getting into the pool. Where we are rains aren't so much the problem - it's more the wind blowing leaves and debris into the pool.

Anyway I was just out there and on closer inspection I don't think it's going to be too much of a problem. The top (deck) section of the skimmer definitely can be moved up and down, and indeed to try and cope with the existing slope I can see that the outside edge of it is much lower than the inside, ie it's not on flat level with the skimmer body. In fact, it's on at such an angle that the side facing the pool doesn't quite touch the body of the skimmer - hence why there's putty trying to seal the gap (see photos)!

I've put a level across from the outside edge of the existing coping to the outside edge of the skimmer lid (see photo), and actually - even allowing for the new coping being nearly an inch lower at the edge than the existing - the outer edge of the skimmer lid is about a half an inch lower still (and it's possible to move it a tad lower, if needed). So if the lid were set on level it would be comfortably low enough to sit flush with the level of the new paving. I think all I have to do now is order a replacement top part and clean the putty off of the main skimmer part that'll be retained (assuming I don't wreck it when taking up the existing paving - which presumably would mean breaking out the skimmer, which sounds non-trivial to say the least, so let's hope that doesn't happen!).

Thanks again for all your help!

 

[kimkats]

Sounds like I was spot on with my thinking. Glad it was helpful and you have a solid plan to move forward.

Kim

 

[gregch]

Time to share my next concern, I hope this is OK... regarding the paving around the pool. It's basically concrete "reconstituted stone" paving/tiling, in 1" thick slabs (matches the depth of the outside edge of the copings). Of course I'll need to ensure I've got a level base that's completely stable. That likely means scraping off a bit of the surface area to level it off, and laying down a sub-base of compacted hoggin (what we in the UK would call MOT type1) and then a cement bed for the paving.

My concern here is whether running a compactor over the material close to the pool is likely to cause me any problems with the pool sides (which are formed from concrete blocks), or with the parts of pool infrastructure in the ground (skimmer and such) which are old and likely quite brittle. Can anyone share some pointers on how to approach this?

A secondary question is how can I best keep errant building materials, dust, etc from falling into the skimmer once the lid and lid support are removed?? My plan is simply to fix some plastic over the hole but maybe there's a more professional method?

 

[kimkats]

One thing I am going to come back to is the worry of water flowing from the decking into the pool during heavy rains. I would NOT make it level. I would have it with a slight slope from the pool to the grass to help keep this from happen.

-tamping down-it does not seem as if you will be taking off and adding enough to really worry about compaction with a machine. I think you could be by with a manual "stomper". I made one for our barn floor we made into a garage. I had to do quite a bit of digging old stuff up and out and leveling. I used a metal tong rake to do the leveling then used a piece of thick plywood on the end of a 4x4 post as a stomper/pounder . It worked great THEN I watered it real good to help it settle even more.

skimmer cover-I would put a piece of wood over it with a large block like a cinder block on top of it. This will make sure no one will step on it as is my worry with plastic.

 

[gregch]

Thanks for all the useful insights! Yes, I think you're right about the rainwater... we'll try to get an appropriate slight fall so rainwater will flow across to the grass. I even wondered about cutting in a drain/soakaway where the paving meets the grass.

I also think maybe manual tamping (not as creative as yours, but I actually have a 8" cast iron tamper) - at least around the edge of the pool and skimmer area - might be the way to go. Also, the wood + cinder block on top of the skimmer is a great idea. I hadn't thought about the danger of putting a foot through plastic which is ridiculous because I've already managed to put my foot in it one or twice when I had the lid off!! (happily nothing damaged but my pride)

 

[Jayphil]

Like others have said the slop is important, aim for 1/4" for each foot (2% slope) to keep the dirty water away from the pool.
Good luck with your project.

 

[gregch]

This is very helpful, thank you.

 

[Bill1974]

You should base all your final paved heights off the top of your new coping. All the paved surfaces should be sloped away from the pool. Managing how and where rain can be directed away and around the pool is critical. I just when though a similar reno I had to have a drain pipe and drywell installed to handle the rain on one side of my pool where the paved area runs into a retaining wall.

I would assume the ground around you pool is pretty well compacted and settling should be minimal concern. I would only compact the soil when the pool is full. If you use a screened crushed stone for your base it will require minimal compaction. Don't use an expansive soil for a base even if you can compact it. Are you planning of concrete or pavers around the pool? if pavers are you planning on installing them on a concreate slab or not. Is the ground in you area clay or drain well?

It looks like the area around the paved area is higher all around, you may want to bring that down and grade some swales in it yo direct water away.

 

[gregch]

You should base all your final paved heights off the top of your new coping. All the paved surfaces should be sloped away from the pool. Managing how and where rain can be directed away and around the pool is critical. I just when though a similar reno I had to have a drain pipe and drywell installed to handle the rain on one side of my pool where the paved area runs into a retaining wall.

I would assume the ground around you pool is pretty well compacted and settling should be minimal concern. I would only compact the soil when the pool is full. If you use a screened crushed stone for your base it will require minimal compaction. Don't use an expansive soil for a base even if you can compact it. Are you planning of concrete or pavers around the pool? if pavers are you planning on installing them on a concreate slab or not. Is the ground in you area clay or drain well?

It looks like the area around the paved area is higher all around, you may want to bring that down and grade some swales in it yo direct water away.

Sorry for the delayed response and thanks for this info. The copings are shaped (see photo) so hopefully will help very slightly to keep stuff from going in the pool, but I think we will need to put some falls onto the paved area; right now not sure whether to also put in a drain+drywell into the lowest edge (it'll abut a planted area at that point). We are on clay here, so natural drainage isn't great!

We're going to put down 'reconstituted stone' (aka concrete!) paver slabs which match the copings, but the slabs are only 1" thick, so we'll pour a concrete slab over the area to lay them onto. The concrete will have a sub-base of compacted crushed stone. The paved area is about 750 sq ft so most of the crushed stone (what we'd call MOT in the UK) will be mechanically compacted, but I might like to compact manually immediately around the pool edge and skimmer etc.

Some way to go yet though, I have to somehow remove all the old cement from the top of the pool wall, sadly it also seems the liner lock was put down onto a thin bed of cement and I think that and the line lock will all need to come off and new liner lock put down - might be a problem given the liner was ordered to measurements based on the existing liner lock position...

 

[Bill1974]

I went though this last year with my pool reno (It started out as a new liner). On one side I ended up having to leave a small strip without pavers (on the right next to the retaining wall) to allow water to drain into a French drain that runs to a drywell under the lawn. Under the pavers is a concrete slab, and the pavers are set on an inch or so of sand. Without doing this water would have pooled where the patio and retaining wall meet. Water did sit in a few spot with the original patio.

 

[gregch]

That looks great, and the French drain you put in is a really neat-looking solution (incidentally, I just took a look at your 'liner replacement' thread and you've done an incredible job!).

I've attached a plan of mine; my current thinking is to put in a French drain across where the red dashed line is, taking surface water to a dry well in the planted areas. (The land naturally falls gently from the right to the left of the plan).

I now have a potentially bigger question...! I had a call last night with the guy who was going to do the paving. I think he's having second thoughts and in any case is a little bogged down in another job. He's now suggesting that we need to pour 8" of steel-grid-reinforced concrete across the whole area which seems to me massively over-engineered? (I'm no engineer, though).

I accept that our slabs are only 1" thick, so will likely need to be laid down on a full cement bed rather than just dabbed onto compacted crushed stone, and I even get that pouring a concrete base over the area might be a good idea, but wasn't anticipating such serious engineering.

I also have a concern that if, at some point in the future, the buried pipework develops an issue and needs digging out, we would have to cut through and break out 750 sq ft of 8" thick steel reinforced concrete, which doesn't sound trivial!!

 

[gregch]

Apologies in advance if it's bad form to reply to your own post! So I've now spoken to some other people and the consensus seems to be that it should be fine to put down a sub-base of 6" of compacted crushed stone and then pave onto that, laying our concrete paving slabs onto a bed of cement/mortar - that is, the reinforced concrete slab shouldn't be necessary. I have yet to convince the guy doing it, though.

 

[kimkats]

This is YOUR thread. You can reply and add to when ever you want!

I hope your guy doing the work gets on board fast! Lets get this DONE!

 

[Bill1974]

It depends on what works in you area. 8 inch reinforced slab seems a bit excessive. Where I am I have seen it done with a slab, slab with holes for drainage to drains under the slab and w/o a slab on a permeable base. If you don't have freezing and thawing that is one less thing to be concerned with, if you have well draining non expansive soil that too make things easier. You could also go by what the Paver mfg requires. The reality is there are many way to do it. what is important is that water is shed away from the pool and also not permitted to puddle or ruin the underling support material.

 

[gregch]

Having now spoken to a bunch of people, we're now going to go with a 3 inch concrete slab on top of a sub base of crushed stone. We'll lay our paving slabs onto the concrete slab (onto a shallow bed of sand and cement mortar). Apart from anything else, the slab will help to get exactly the falls to drainage that we need. Hope that all sounds sensible!

Before we do it, though... I've another concern I'd love to get some opinions on. The thought occurred to me that if the buried pipes between the pool and the pump etc developed a leak at some point, we would have to break up the new paving and excavate the pipes. Right now there's no evident issue - no sign of any water or pressure loss - but the pool was originally put in a long time ago and I wonder if the pipework has a finite lifespan.

A family member suggested that we should really do it 'properly' and excavate and replace the plumbing before we pave the surround, while we have a digger on site. My concern is that if we start disturbing stuff to that extent, there's a risk of causing more issues - for example damage to the main drain or pool floor, or ending up having to break out the skimmer and rebuild the pool wall, etc. When right now there's no issue. Added to which, I'd really just intended to replace the liner and freshen up the pool surround as economically as possible and it's already stretching finances to the limit! So, do I dig out and replace the pipes, or leave them be??

 

[Bill1974]

I redid everything on my pool last year, (liner, coping, lines, skimmers, returns, and decking etc). Do you know what material your line are? My pool is from the early 80's I think, but when I redid mine least it I think I discovered it was the 4th or 5th time they were done. I found thin green PVC that would crumble just looking at, two sets of black poly lines (these looked fine) and what was in place was white flexible PVC lines (the inside was deteriorating). I replaced all with rigid schedule 40 PVC. I would stay if you have lines that are working fine, no leaks (do a pressure test) and of a material that does deteriorate in your area, leave them be.

I completely understand that idea of never wanting to have to deal with them once everything is done. But with pavers even over a slab, it can be worked on if needed and put back to look like it was never touched.

FYI when the slab is poured don't expect it to be troweled like a finished concreate surface, it will be a bit rough. Ideally it will be floated so water will not puddle on it. Again that is ideally. Mine was not perfect but, it only had a few areas where only the 1/8" of water would sit as best. Also, ready what the paver mfg recommends for a subbase and make sure that is followed.

 

[gregch]

Firstly thanks for the insights, very helpful. We'd decided to leave the pipes be (it's 1.5 inch ABS pipe with decent wall thickness and in reasonable shape as far as we can tell) but have accidentally exposed part of the run during excavation... doesn't seem to have caused any damage to the pipes so we'll cover over with shingle before the crushed stone goes over and gets compacted - hopefully they'll survive OK!

Another discovery while excavating is the very poor state of the ground, it's clay and pretty squishy, so we're going to put a decent depth of compacted stone and concrete over. We're aiming for falls away from the pool and overall down to the bottom edge of the site (the natural fall of the land). There we've dug a drainage trench which will be filled with a perforated pipe bedded in shingle and leading down to a dry well which has been dug to 7 ft and backfilled with stone, with membrane over to protect from soil ingress. That should manage drainage, and will all be covered over at the surface with topsoil and lawn.

Final, seems like a fairly trivial issue but causing me a bit of concern... inevitably during the work a big chunk of excavated dirt has got dumped into the pool (we've kept the pool full of water so far so as to help hold everything in place until we're ready to do the liner change). We've also left the pump running to keep the water clear and stop the water in the filter sand from going stagnant and unpleasant. My concern is whether the soil, dirt and general building muck currently sitting on the bottom of the pool will end up down the drain and silt up the pipework underground. I'll go down and try to scoop out what I can out of the pool (don't know what with, I guess leaf net!) but should I be concerned? Obviously there's no way to really cover the pool over while we're working on the surround.