What’s this anyone?

[Fishandchips]

Hi guys,

Just doing some work on my new to me house. The house is built on a concrete slab covered with 20mm of bitumen type stuff.

It’s breaking free as I am pulling up some stuck down oak board.

Anyone know. What it is please?

After I have made a real mess how can I repair it ?

Cheers

View attachment IMG_1362.jpeg

 

[toolsntat]

I think it's most likely be asphalt, opening a can of worms there.
I'd not be taking it up if possible.
Cheers, Andy

 

[Bingy man]

Agree with above , caution as some ashphalt can also contain asbestos - if concerned leave alone and have it tested.

 

[Myfordman]

It is possible that the asphalt is providing the damp proof course to the floor.

 

[BradyS]

Weird stuff you guys have in your floors. My friend in London worked in construction for a while years ago when he got there. Showed me a lot of under-flooring done last century, from weird to disturbing.

I'm 95% sure it's a mixture of asphalt. We used to use a similar material in Romania for rooftop insulation on apartment buildings (blocks of flats). Up until the late 2000s, it was teh preferred thermal insulation method. Not very efficient as it was laid down on a paper substrate (asphalt cardboard) and the seams were "welded" with that mixture.

Your flooring seems glued onto that material with something resembling polyurethane/foam adhesive.

I wouldn't recommend taking it down either, not only because of the worms but it can contain many otherharmful substances besides asbestos. If you have a respirator or similar breathing protection, the piece you need to put back can be welded by using a blowtorch. Although I would recommend either leaving that to a professsional or using some glue, PU or similar (don't apply much, it will expand). In my opinion, if you don't glue it back chances are your floor will wobble in that area.

Cheers!

 

[Bingy man]

I have it all over most of my flat , it’s the original top coat on top of very rough concrete ( no screed ) not sure if it was to prevent damp but very possible. Had an asbestos report done a few years back but the ashphalt was negative. It’s been removed In my kitchen and bathroom and replaced with screed - no evidence of damp in over 10 years .

 

[Stigmorgan]

As already mentioned you need to be very careful, bitumen adhesives are known for containing asbestos, I would strongly recomend getting it tested before disturbing any more of it.

 

[Fishandchips]

I think it's most likely be asphalt, opening a can of worms there.
I'd not be taking it up if possible.
Cheers,

 

[Fishandchips]

Thanks guys,

Didn’t know about the asbestos, I’ll leave it where it is.

I am managing slowly by cutting through the oak into small sections. It does not seem to have the same suction effect lifting the asphalt.

Anyone know how I could soften the glue? Make life a bit easier?

Cheers

 

[MikeJhn]

Anyone know how I could soften the glue? Make life a bit easier?

Cheers

To soften the glue use a Heat gun, the black stuff is probably not Asphalt, but a proprietary waterproofing liquid, used to use lots of it on concrete years ago, can't think of the name at the moment, it will come to me and I will post it up when I remember. (Aqua something or Bituseal I think)

 

[Woodworker Ireland]

It was used to stick down floors mostly oak and other hardwoods. Ive repaired the aile floor in Church recently which had it. I left it alone just used modern adhesive to stick new stuff. It also worked as a vapour barrier. It was heated in a big pot outside and pored on floor.

 

[BradyS]

Thanks guys,

Didn’t know about the asbestos, I’ll leave it where it is.

I am managing slowly by cutting through the oak into small sections. It does not seem to have the same suction effect lifting the asphalt.

Anyone know how I could soften the glue? Make life a bit easier?

Cheers

Depending on the substrate - not sure using a heat gun is a good idea. If it is that proprietary waterproofing material you probably shouldn't use any potentially altering solution. The heat gun might melt the glue and the black thingy as well, hence releasing fumes, maybe even toxic ones, not sure. Just be sure to take all safety measures possible.

 

[toolsntat]

To soften the glue use a Heat gun, the black stuff is probably not Asphalt, but a proprietary waterproofing liquid, used to use lots of it on concrete years ago, can't think of the name at the moment, it will come to me and I will post it up when I remember. (Aqua something or Bituseal I think)

Have you seen the picture?
The liquid we used to call "blackjack" was poured and rollered with no thickness to it, akin to paint.
As for Bitumen this is the stuff you'll normally find under old parquet flooring, easily identifiable from asphalt as it fractures and splinters and gets everywhere.
Asphalt, as I know it and as seen here, has a thicker, less fractured appearance when broken.
Cheers, Andy