self leveling compound heave

[r.bartlett]

Chaps

Some 10 years ago when the new kitchen was done we had the concrete floor self leveled with SLC (by the flooring guy's) All good.

Last year I noticed a slight lump come up near one of the corners. This has gradually grown to 300mm dia and about 30mm at it's highest.

I thought it was my central heating or perhaps the cold water feed. This morning I took up the corner and broke the SLC to look under, It was perfectly dry. Absolutely no sign of damp?

So can SLC just suddenly start to heave for no particular reason as it's left me with a 10mm dip I need to fill with new

TIA

Richard

 

[pinenot]

Presumably so Richard. Put down a good bonding agent when you repair the patch though...pinenot

 

[dann09]

You took up what at the corner? Tile, wood, sheet mats?
How was the covering originally fixed down?

Typically, if there are no damp issues, then movement, as in expansion of whatever is the finished floor covering, might be the culprit, esp. if there is no expansion gap at abutments.

 

[r.bartlett]

it's only lino...

 

[^woody^]

It is not heave, but rather the compound has detached from the floor slab.

Self leveller should be so thin that it would not be possible to lift in one piece, if it has then that would be the reason alone

 

[r.bartlett]

It is not heave, but rather the compound has detached from the floor slab.

Self leveller should be so thin that it would not be possible to lift in one piece, if it has then that would be the reason alone

Detaching is one thing - this is some 30mm risen off the concrete as if someone has blown an air bubble into it?

 

[dann09]

Is the sheet material a full stick down job, or a perimeter stick down, or merely flopped down?
Does the vinyl go under the skirting?
How "thick" is the SLC in the corner with the "heave"?
What is the sub-floor?

An "air" bubble is precisely what it might be, but more info req'd.

I've seen air bubbles under full stuck down, sheet vinyl lift the self levelling compound off the subfloor in patches about 300mm x 300mm.
Some of the bubbles were approx. 15mm to 50mm high. Perhaps damp in the sub-floor played a part, i dont remember.
The SLC depth was from a feathered finish to nothing, to various depths approx. 15mm to 25mm.

SLC, of course, can be bulked up with fibres, fillers, or even dry sand, to, so i'm told, a 50mm depth.