Springy new engineered floor

[IE00]

Hello,

We have had a new floor laid of engineered wood over screeded floor and existing concrete floor, all a continuous area. The floor is very springy where the screeded floor meets the existing concrete floor and in parts of the screeded floor. The screeded floor was very level when it was laid, but somehow the floor feels unsupported in parts. It was laid late November, using a tongue and groove system and the very competent joiner left the required expansion gap.

I am looking for recommendations of what we can do, that does not involve ripping up the whole floor. Please also spare me the reprimand of what should have happened, I have now learnt my lesson to specify the floor should have been supported in places where it felt uneven (although not sure how I could have done that as the screeded floor was level when it was laid), but looking for least-disruptive solutions to move forward.

 

[foxhole]

The screed would have had to fail for there to be unsupported areas after a level screed was applied.

 

[IE00]

Thanks I'm looking for solutions. Any suggestions?

 

[Deleted member 174758]

Two choices I can think of:-

(i) Lift the floor, relevel it and relay. This is the approach I'd take with a newish floor, if possible (and is what we are doing on snagging work right now - it can result in damaged flooring which needs to be replaced). Possibly the underlay is incorrect? Maybe the screed isn't as level as it should be. Possibly MC in the concrete is toohigh and no DPM? What is the sub-floor made of?

(ii) Drill the floor in the springy areas and inject an engineered floor repair, weight down and leave to set. Once the glue has set fill the hole with a matching filler (I prefer to mix hard waxes from Konig to the exact colour - these require a small gas torch to melt them). This is not a repair for the faint of heart and is the repair of last resort. The kits we get are of the DriTac brand (American). Sorry, don't know who the distributor is

 

[tell80]

I know you want solutions but, if possible, its best to try & find causes first.

"where the screeded floor meets the existing concrete floor" - so are you talking about two separate
floors in two separate rooms with an opening between the rooms - eg a kitchen and a dining room?
Or, say, a dining room & a front room?
Are both floors solid or is one floor a suspended floor?
Where the sub-floors meet is it perfectly level?
When you say "screeded" do you mean SLC or a semi-dry sand & cement screed or a brand new concrete?

Do you have UFH?
Do you have min 3mm underlay?

 

[tell80]

Sorry J&K, I didn't realise (its getting late) you had posted quicker and better before me.

You and big-all are first rate in answering these kind of questions.

 

[IE00]

(ii) Drill the floor in the springy areas and inject an engineered floor repair, weight down and leave to set. Once the glue has set fill the hole with a matching filler (I prefer to mix hard waxes from Konig to the exact colour - these require a small gas torch to melt them). This is not a repair for the faint of heart and is the repair of last resort. The kits we get are of the DriTac brand (American). Sorry, don't knopw who the distributor is

Why is this a last resort solution, sounds ideal as it is least disruptive. What does an engineered wood floor repair do? Are you meaning I should nail the floor down?

I know you want solutions but, if possible, its best to try & find causes first.

"where the screeded floor meets the existing concrete floor" - so are you talking about two separate
floors in two separate rooms with an opening between the rooms - eg a kitchen and a dining room?
Or, say, a dining room & a front room?
Are both floors solid or is one floor a suspended floor?
Where the sub-floors meet is it perfectly level?
When you say "screeded" do you mean SLC or a semi-dry sand & cement screed or a brand new concrete?

Do you have UFH?
Do you have min 3mm underlay?

Thanks, it's a kitchen - dining - living room. The living room has existing concrete floor and is cornered off by three walls, the kitchen - dining is the new area with sand screed with a quick drying additive, but the floor was left for triple the recommended drying time due to delays. We do not have UFH and have 5mm of high quality underlay, it's the gold stuff (literally). The floors are level, not perfectly, 2-3cm difference in heights across a 45 sqm area. The floors are solid floors but the engineered wood on top is suspended, fitted with tongue and groove.

 

[Deleted member 174758]

It's the last resort because it effectively glues the flooring to the sub floor, but it doesn't address the underlying problem. If you have an installation where the engineered floor has already been glued to the sub-floor, then fine (maybe) - if your installation is one where the flooring has been floated on top of an underlay with the tongues glued together it can cause you a lot more issues.

You haven't said how the floor was installed (floating or glued down, underlay or not, sub-floor screeded or not). It would be helpful if you could say. You say that part of the floor is over a concrete, so was a DPM put down on the concrete section (normally a liquid DPM would be a blue or green colour, but I hsve used clear epoxy seslants in the past) - and was the floor checked with a moisture meter such as a Tramex to gauge the MC before the DPM or flooring went down? All significant details

The floors are level, not perfectly, 2-3cm difference in heights across a 45 sqm area. The floors are solid floors but the engineered wood on top is suspended, fitted with tongue and groove.

Are you sure? 2 to 3 cm (20 to 30 mm)? Any joiner installing joists or cladding them with boards or planks is aiming for a discrepancy of no more than 2 or 3 mm. If the variation really is 20mm or more then there is something very wrong with that sub-floor and that will need to be adressed if you are ever to get an effective fix