Another Self Levelling/ DPM Question

[1andrea]

Hi

I am looking for a bit of advice if one of you kind professionals can help.

I want to install solid wood flooring in my basement flat over a ribbon system underfloor heating (This type of underfloor heating is suitable for solid wood due to the ribbons covering a larger surface area than the wire systems so a lower temperature is needed to make them suitable to be used under wood apparently)

The floor is concrete and is uneven in places (don't think its newly done but cant be sure) so I am going to use self levelling compound to fix it.

I am worried about moisture and damp coming up through the concrete, one part of the floor already has this and is being repaired by the management company.

The underground walls have been tanked and an injection dpc has also been installed.

Do I need to install a liquid dpm before levelling or will a damp membrane do the trick? I haven't checked for relative humidity as I don't have a hygrometer.

Do you think I should install a liquid dpm or a damp membrane to be on the safe side anyway regardless of the humidity as it is a basement flat.

Do I need to prime the concrete before using the self levelling compound?

And finally what self levelling compound will be best for my situation?

Thanks for taking the time to read this

Andrea

 

[WoodYouLike]

Andrea

I leave the answering of the moist ect to others, but we recommend strongly you install wood-engineered flooring on UFH (or if you are set on solid small widths boards, not wider than 110mm)

 

[joe-90]

I would have thought (though others may not agree) that you would be able to get away with using a latex leveling compound onto which you lay an insulating type of flooring board down on which to lay your new floor. The reason for the insulating board is that the heat from your ribbon cable will go straight into the concrete and much of the heat you pay for will be lost.

 

[mattysupra]

First you need find out the moister reading of the floor. You dont want to putting down epoxy dpm if you dont need it. Also i dont know any solids that are recommend on being fitted below ground level. You should be installing engineered wood like 'woodyoulike' suggested, and more so with underfloor heating. I would use acrylic based compound also. Latex has a weak shear strength. I would also re think the under floor heating thing to. Really is more hassel than its worth. You do realise that you cant just come home and turn it on when you feel a bit cold. Or even if too hot. You turn it off but it still gives out heat for a fair while after.

 

[1andrea]

First you need find out the moister reading of the floor. You dont want to putting down epoxy dpm if you dont need it. Also i dont know any solids that are recommend on being fitted below ground level. You should be installing engineered wood like 'woodyoulike' suggested, and more so with underfloor heating. I would use acrylic based compound also. Latex has a weak shear strength. I would also re think the under floor heating thing to. Really is more hassel than its worth. You do realise that you cant just come home and turn it on when you feel a bit cold. Or even if too hot. You turn it off but it still gives out heat for a fair while after.

I have been thinking about engineered flooring a lot but am struggling to find a single plank oak for less than £20 per metre.

I have seen a single plank 7mm KAHRS from the Linnea range that is £18.50 per metre plus Vat which is a bit over budget. It is a nice colour single plank with a locking joint and 12 year guarantee.

Do you have any experience of kahrs flooring?

Underfloor heating is the only option for me as there is no Gas in the apartment building and I am limited on space for wall heaters but don't really want them anyway cos they are ugly.

Thanks for the reply

Andrea

 

[joe-90]

First you need find out the moister reading of the floor.

There's little point in that as it will change due to capillary action once the leveling compound is down.

 

[mattysupra]

shut up you fool.

 

[mattysupra]

andrea,

kahrs flooring is a very good flooring. I used to use it but not anymore. I think you may struggle to find much tho on that budget. But if you can save on dpm will you not have a bigger budget? epoxy treatment is very expensive.

 

[1andrea]

Matty

Given my situation would you go for the KAHRS instead of solid oak?

Will a damp membrane work ok with this instead of installing a liquid dpm?

Thanks
Andrea

 

[joe-90]

shut up you fool.

Sorry if the science leaves you behind. BTW, what do sheer forces have to do with anything?

 

[mattysupra]

yes i would go for the kahrs. You could really do with some sort of moister reading tho. You may be able to get away with a combi underlay.

 

[1andrea]

Where do i get a moisture reader from?

Would I do the test before or after the floor is levelled?

Thanks

Andrea

 

[mattysupra]

joe lets say that the heating system needs to be bonded to the 'latex' or maybe you want to lay surface dpm on top of the 'latex' compound??? As they asked in there original question. Well guess what joe??? You cant put epoxy dpm onto latex! Reason being is that its shear strength is not higher enough to take the pressure it will encounter. Or maybe they want to glue a wooden floor to it? Well you cant do that either. Plus its compression strength is also weak, so if you decide to install lets say karndean, lino etc you can damage the flooring with heavy items. And what you talking about with science? You want to challenge me on how moister etc works? i think not.

 

[mattysupra]

Hi andrea. You need to know the moister of the subfloor before you do the floor prep as this will make the difference to what compounds or even dpm treatment you want to do. Can you not get who ever doing the dpm work to test the subfloor? If not the only way to test the floor yourself is to buy the equipment. Going to cost you maybe 100+ quid tho.

 

[1andrea]

Matty

I will ask if they have the equipment to check the floor.

Can the equipment be hired from the HSS hire shop?

Thanks