Readying screed for engineered flooring

[paro]

Hi All,

 

I went for the cement flowing screed based on the the recommendation from the screed company that this was more suited to glue down flooring.  I am planning to do this myself with herringbone engineered oak (18mm).  The floor is level (55m2) with some minor bumps and imperfections (and acorns apparently...). I was expecting to be able to glue the wood down direct with no more than a good hoover up before hand but am now nervous that this isn't enough so am questioning whether any further sanding/levelling, priming is needed. 

 

I see from a previous post its been suggested the glue thickness for herringbone is insufficient to mask anything but a completely flat floor.  How much tollerance does herringbone have?

 

There are a couple of transitions I need to factor in as well. On one side I have bifolds (3.3m+2.8m) and the other is the cottages brick floor (3.6m).  The remainder of the floor has 25mm PIR + the blue expansion strip all round so not concerned there but ideally I'd like the gap around the transitions to be as small as possible for a cleaner look. Two questions here, how small can that expansion gap be and if it's got to be more than say 10mm are there any nice looking products available for creating a neat/seamless looking transition.

 

Thanks, Paul

 

 

[Russell griffiths]

Unless you have a fair bit of experience I would forget herringbone and use a plank, far more forgiving 

[paro]

None whatsover and to be fair the videos I've watched haven't made it look any easier. Thanks.

[saveasteading]

1 hour ago, paro said:

a completely flat floor

What does that mean? 

There are definitions for flatness  and super-flatness. 

Flat can include being on a slope in one direction.

 

It is usually measured, if at all,  by placing a 3m straight edge on the floor in all directions,  and measuring gaps. Up to a 3mm gap at any point  is 'flat'.  Or do a survey on a grid. The spec is whatever you want it to be.

For better than that , a super-flat floor, the top needs grinding off.

 

So I can't advise, and I suspect the manufacturers are quiet on it too.

But thick glue will be the answer. 

[Oz07]

Without looking into i'd imagine herringbone is more forgiving on the flatness of subfloor as its smaller units. I could be wrong though. I imagine most flooring pros nowadays always want to latex. They know what they're going onto then.