Main drains set too low in concrete pool, any thoughts

[Indoorpooluk]

Hello all
Constructing an indoor swimming pool in the uk and struggling to overcome this.
I plan on laying 75mm insulation (xps insulation already bought) and then screed on top of the concrete, as you can see the main drains are set too low
I have found a seperate part that could be solvent bonded to the insitu drain to increase the height by 38mm but its still too short
Any ideas, i cant face digging up the concrete and reinstalling
I guess this problem has come up before where older pools without insulation update.
Any thoughts and thanks for reading

 

[kimkats]

plan on laying 75mm insulation (xps insulation already bought) and then screed on top of the concrete,

I am not following what the above means. The next thing should be the plaster. More info is needed to help us help you.

 

[ajw22]

Welcome to TFP.

Explain in more detail the buildup of materials you intend from the concrete.

How thick will the materials be? How long do you need to extend the drain?

In the US the concrete gets a layer of plaster which your drain would accommodate. Any insulation should have been placed before the concrete.

 

[Indoorpooluk]

Hi all
Unfortunately no insulation under the concrete and the two main drains have been set too low
I planned to lay 75mm insulation on to the concrete and then screed on top, the drains will therefore be approx 100mm below finished floor level but if i cement solvent bond the drain in the pictures to the original drain finished floor level is still 65mm higher which maybe could be dished in the screed
Thanks for looking, my inexperience is showing but grateful for any ideas

 

[kimkats]

The ground under the shell will act as insulation. Seems to me the insulation on top of the shell will cause many problems down the road. Most of the heat is lost from the open top of a pool.

 

[ajw22]

I do not know what material "screed on top" is. Is that British English name for plaster?

 

[Indoorpooluk]

Hi
Yes screed is plaster to go on top of the insulation board

 

[ajw22]

This site talks about XPS insulation being below the concrete slab.

Swimming Pool Insulation Guide

Can Insulation Make your Pool More Energy Efficient? Although nothing beats a peaceful summer afternoon spend beside your own swimming pool free of noise or any other disturbance, not a lot of people are aware of the fact that pools can be a massive energy consumers. Namely, it takes a vast amount

www.insulationshop.co

Do you know of pools in your area that have plaster applied on top of XPS insulation? I would think it would not be a stable enough base for plaster. The plaster may crack and leak. And if water leaks behind the plaster where will it go? With plaster on-top of concrete when water gets behind the plaster the concrete is porous and the water drains into the ground.

@onBalance what are your thoughts about plaster on top of xps insulation boards on a concrete pool floor?

 

[onBalance]

I do not have any experience with this. My thoughts are, unless the pool shell is actually up out of the ground and exposed to the weather, I see no reason to install insulation boards. I also would be concerned about the effectiveness of BONDING the new plaster to the insulation boards, and the boards would have to be very VERY rigid to avoid any flexibility that would cause the plaster to crack.

 

[mas985]

Conductive heat loss is generally the smallest component of total heat loss of a swimming pool (< 10%) and since concrete has fairly low thermal conductivity to begin with, the extra insulation isn't likely to change the heat loss characteristics of the pool very much

 

[jimmythegreek]

I wouldnt install insulation above the concrete it will come back to bite you. Any ridgid insulation is placed under the floor and honestly you wont ever know the difference. Plaster needs to adhere to a surface with zero deflection. The majority of heat loss is rise thru evaporation, the floor amd walls are naturally insulated via the earth. The only thing worth insulating is the walls amd then the top via an auto cover or solar blanket. Dont waste your time and effort on the floor you will have plaster issues down the road

 

[BoringDamo]

Screed isn’t plaster. It’s often used in the uk on top of a concrete (or concrete beams) and insulation base. The screed provides a smoother finish than concrete so you can lay carpet on top of it.
(Why You Might Need to Screed a Concrete Floor - Concrete Flooring Solutions). I’ve just had this on the ground floor of my new build house but I’ve no clue about it in pools!!

 

[sktn77a]

I'd just apply the final finish (plaster/screed) directly to the existing concrete.

 

[jimmythegreek]

I'm familiar with screed we use it in Greece as well. Theres a limited amount of weight that can be placed on it. When post and beams are set, they are all built first and the screeding goes up to them amd around them.
So in a pool, the whole floor is structural as it carries the load of the water which is very heavy depending on gallons of course. You wouldnt place load bearing supports over screeding, just as you never place water load on it