Removing Parquet Flooring and Replacing with a Screed

[Willmott85]

Afternoon All,

We'd like to lay some engineered oak flooring in our entrance hall, but the current floor is the original 1930's parquet flooring that is far from level, or flat.

It's clear that I cannot just lay a levelling compound over the parquet flooring, so it looks like I need to lift it all up, and lay a concrete slab/screed in its place.

The thickness will vary, but will need to be about 20-30mm, over an area of about 10m2.

Is this too thin for a screed? If it is ok, what prep would you recommend before hand (e.g. primer) and what mix for the screed?

What alternatives do I have if it is too thin?

Appreciate any help you are able to give. Cheers, Adam

 

[Ivor Windybottom]

The bitumen-based adhesive holding the parquet may be the one and only means of damp-proofing. So you'll need to replace it with something else, either above or below the screed. Possibly an epoxy coating, I don't know.

Get a sample of the adhesive tested beforehand, it may contain asbestos fibres. It's unlikely to become airborne with scraping, but this would mean you definitely don't want to use power tools on it. Perhaps spray it with water before scraping. Get specialist advice, I'm guessing.

Someone on ebay might pay for your bagged up parquet, so keep it. Don't use it as firewood, it will be full of bitumen (possibly with asbestos), linseed oil and unknown varnishes.

 

[Willmott85]

The bitumen-based adhesive holding the parquet may be the one and only means of damp-proofing. So you'll need to replace it with something else, either above or below the screed. Possibly an epoxy coating, I don't know.

Get a sample of the adhesive tested beforehand, it may contain asbestos fibres. It's unlikely to become airborne with scraping, but this would mean you definitely don't want to use power tools on it. Perhaps spray it with water before scraping. Get specialist advice, I'm guessing.

Someone on ebay might pay for your bagged up parquet, so keep it. Don't use it as firewood, it will be full of bitumen (possibly with asbestos), linseed oil and unknown varnishes.

Thanks, didn't think of asbestos in it.

I was hoping I could just put a damp proof/primer on top of the bitumen. Is this not acceptable?

 

[Ivor Windybottom]

I don't know. I've got the same issue to deal with in our house, haven't really started looking at options.

Bitumen is soft, I'd worry a skim of screed could crack if on top of it. But it may be fine, as it's not compressible. I don't know what is best practice or how to remove it.

Check more on the asbestos. I'd read it was sometimes included in adhesive, I assume as reinforcing binder fibres. Possibly not in the 1930s, more likely in our 1950s house, when they seemed to be chucking it in everything including lino tiles. But be sure before starting.

Hopefully someone here knows more, I only know it's not simple!

 

[justigator]

Engineered oak flooring is nice - just fitted such a floor myself - but so is parquet. Have you considered sanding, or having sanded, the existing parquet? My current house had it on most of the ground floor, in very poor condition. 35 square metres. Had it professionally sanded for £600 in 2019 and was very pleased with the result. Even two coats of Osmo with a 2 inch paintbrush afterwards wasn't too hard. No need to remove skirting etc.

 

[Ivor Windybottom]

If the concrete underneath has sunk then it's beyond sanding, and would probably look naff if pulled up and re-laid.

 

[Willmott85]

Engineered oak flooring is nice - just fitted such a floor myself - but so is parquet. Have you considered sanding, or having sanded, the existing parquet? My current house had it on most of the ground floor, in very poor condition. 35 square metres. Had it professionally sanded for £600 in 2019 and was very pleased with the result. Even two coats of Osmo with a 2 inch paintbrush afterwards wasn't too hard. No need to remove skirting etc.

As @Ivor Windybottom has said, the sub layer has sunk over the years so its well out of level, and flatness. So will need to be pulled, new subfloor, and relaid.

However, we have laid engineered oak throughout the rest of the downstairs, so we'd like to continue that into the last room, the entrance hall.

It is a shame to pull up the parquet, as it would look beautiful with a lot of work put into it, but it doesn't go with the rest of the house.

I have been on to Ardex yesterday. They have Arditex NA which is specifically designed for going over bitumen (amongst other old substate types). So I will remove the parquest, and self level with that product.

Just need to decide now whether to self level the full 30mm, or do a 10mm slc, with 20mm rigid PIR insulation on top, to add a bit of warmth. Anyone know if this is possible?

 

[johnny2007]

I've had the same done in my house.
My advice:
Lift a bit of parquet and get the adhesive tested for asbestos.
Mine didn't have any so i proceeded to remove the lot with a shovel, it came up pretty easily.
I scraped off the adhesive with a hoe so I didn't break my back.
I had almost 50m² to do, so I decided to call the professionals in.
Best decision of my life.
The results were impressive.
Later I laid tiles in part of it and wooden floor on the rest, a total breeze.
My original screed has a layer of bitumen underneath it, but these screed guys used a liquid barrier anyway before the levelling compound.
The original screed was on a slight slope that over 11 metres resulted in 60mm difference; they sorted that and now everything is levelled.
£1600 all in and was very worth it.
If you can, get the professionals to do it.

 

[Willmott85]

I've had the same done in my house.
My advice:
Lift a bit of parquet and get the adhesive tested for asbestos.
Mine didn't have any so i proceeded to remove the lot with a shovel, it came up pretty easily.
I scraped off the adhesive with a hoe so I didn't break my back.
I had almost 50m² to do, so I decided to call the professionals in.
Best decision of my life.
The results were impressive.
Later I laid tiles in part of it and wooden floor on the rest, a total breeze.
My original screed has a layer of bitumen underneath it, but these screed guys used a liquid barrier anyway before the levelling compound.
The original screed was on a slight slope that over 11 metres resulted in 60mm difference; they sorted that and now everything is levelled.
£1600 all in and was very worth it.
If you can, get the professionals to do it.

Thanks for the reply Johnny.

This is only a small area ~10m2, so not a big space. A number of the parquet sections are loose anyway, and a few that are not, can be lifted without much effort. So clearing the space should not be too difficult. Certainly something that I would do myself.

you say "My original screed has a layer of bitumen underneath ". So did you have parquet, bitumen underneath, screed, and then another layer of bitumen?

I don't actually know what is under the bitumen if my place. It most likely is a screed/slab of some kind.

I was planning to leave the bitumen in place and just used the Arditex NA over the top. Which was recommended by Ardex themselves.

It's more the best way to bring the level back up ~30mm:

- Full layer of SLC
- Partical SLC with rigid PIR insulation on top
- Full layer of screed

 

[johnny2007]

The layers were from top: parquet, bitumen adhesive, concrete screed (roughly 80mm), liquid bitumen membrane.
I know because I removed some collapsed concrete.
There are several self levelling compounds that can be laid up to a depth of 80mm.
That would be the easiest solution.

 

[Willmott85]

The layers were from top: parquet, bitumen adhesive, concrete screed (roughly 80mm), liquid bitumen membrane.
I know because I removed some collapsed concrete.
There are several self levelling compounds that can be laid up to a depth of 80mm.
That would be the easiest solution.

ok, thats clear.

Have since spoken to Lecol about their range, in particular Z520. Seems a better bet than the Arditex NA. More info here for any future reference:

Levelling a bitumen sub floor - Lecol UK

Lecol - Read more about how to level a bitumen sub floor and find your nearest Wakol distributor!

lecoluk.com