Warmup - raised floor problem

[Joliver1987]

Hello,

If anyone can have a look at the attached. Warm up sticky mats have been used with warmup insulation boards. Floor levelling screed and then Karndean flooring. 
 

You can see a raised section in the floor coming through and has been slowly getting worse over the past few weeks. 
 

Thanks to any experts in this area! 
 

<a href="https://ibb.co/nf9QZ6H"><img src="https://i.ibb.co/k0jqk5R/8-AE53792-DA38-4213-958-B-CCA7444-E6-F86.jpg" alt="8-AE53792-DA38-4213-958-B-CCA7444-E6-F86" border="0"></a>

 

[Joliver1987]

https://ibb.co/nf9QZ6H

 

[ProDave]

I would say address the problem to whoever laid the floor.  I suspect the whole lot will have to come up and be re done.

What is the underlying floor that this was laid over?  Timber? Concrete? Other?

 

[Joliver1987]

Thanks Dave. My understanding is:

1 - suspended timber floor 60’s

2 - Ply 

3 - pro warm boards and sticky mat

4 - Concrete screed

5- Karndean

 

[Murdoch]

Your first post of call is to the Karndean installer to see what they say , then the installer of the underfloor heating system

Thanks Dave. My understanding is:

1 - suspended timber floor 60’s

2 - Ply 

3 - pro warm boards and sticky mat

4 - Concrete screed

5- Karndean

As a thought did the karndean installer put anything down before their finished floor?

that looks quite a big room - did you have any walls down?

 

[kerching]

What @ProDavesaid!

looks expensive

who laid it and what is the sub floor?

 

[Joliver1987]

Not a cheap job. Our builders who opened up a large living space laid the pro warm in kitchen and dining room. The problem areas seem to be where the underfloor section meets the living room which does not have pro warm. 
 

They used 6 and 12mm plys and screeded the whole space to get a level surface rather than feathering. 
 

https://ibb.co/DCJyznG
https://ibb.co/w6FBdgT

These images might provide so context as to how the space has been opened up and that both raised areas are at the very edge of the pro warm system where it meets the living room that is standard floor with no system. 
 

I’ve just started speaking with both parties. 
 

Thanks for the brilliant replies already. 

 

[Murdoch]

Hum ......... last time I saw something like this was caused by the wood resting on the remains of the wall below - that was easily fixed but didn't have an electric element running though it!

good photos and communication

 

[ProDave]

It's not clear if all the work was done by one company (sub floor ufh mat, screed and final floor)

If not the blame game will start with each blaming another.

 

[Sharpend]

How long was concrete allowed to dry prior to heat mat being switched on? 

 

[Joliver1987]

Both trades are close friends so I’m sure they will do everything to help resolve it. 
 

builder: laid ply, mats, pro warm

floorer: screed to cover and protect system. Back 2 weeks later for 2nd screed layer across whole living space. Flooring down a week later. 
 

System would of been on for testing after screed layers had dried 48 hours later. But whole system not on and running until flooring was finished. 
 

Would a pro warm system expand the screed slightly from the heat. Which would explain why the problem is right on the boundary between the pro warm system and non pro warm space. 
 

Here are two photos showing the finished screed between living space (not heated) and kitchen (heated)

https://ibb.co/7XkGDn2
https://ibb.co/y6pgqgG

 

[Sharpend]

Was there any other heating in the room when screed was laid?
We have had some seriously cold weather recently and concrete should not be mixed/poured in cold temperatures. 

 

[Sharpend]

Industry guidance: 

Temperature limits – If young screed is allowed to cure and dry below the freezing point, it will probably be unfit for use. To avoid this, two different temperatures must be considered: 1) ambient air temperature, which should not go below 3°C; 2) floor temperature, which should be maintained at 5°C. If screed is laid below 0°C, the water will freeze and expand by about 9 percent. This could cause a disruptive reaction and make the screed break.

Curing and drying times – Most screeds settle and develop strength within five days if kept dry, at or above 5°C. The best way to protect the screed in wet or cold weather is to use polyethylene sheets. These sheets prevent the heat generated by the chemical reactions (e.g. hydration and hydrolysis) in screeds from dissipating, keeping the screed warm enough to cure and dry properly. Additionally, polyethylene sheets can help avoid rain water splashing onto freshly applied screed, significantly lowering the risk of failure.

Polythene curing should only remain in place for 7 days and then removed to allow the screed to dry. In general, water evaporates from the surface and it’s good practice to exchange the air 3 times a day by opening the windows giving good airflow.

Since bad weather extends curing and drying times, and may prevent screeds from drying properly within the set time frames, testing is very important, as it provides contractors and owners with valuable information regarding the characteristics of the screed.

 

[Geoff1946]

If there are heated and unheated areas I can't help wondering if there should be some kind of expansion joint to avoid stresses ?