sub floor been laid after plastering

[delboybully]

I have had a single story extension added to my home

The builder said to get the plastering done before the final screed (sub floor). It has been said in other posts of mine that this was the wrong way round but i had already had the plasterer in.

I was told to chop back any excessive plaster off so that the plaster stopped about 12mm above the final floor level before the screed was laid. This i did but i didnt remove the excess of the plasterboard around the cheeks of the patio doors and also around entrance to the extension

Unfortunately at these points the plasterboard has got wet at the bottom (about 2 inches high)

Also where the floor screed was laid in some places there is an excess of screed under the plaster (it is higher than the floor) and in these places, again the plaster has soaked some water up.

Do i need to remove this excess screed and also the plasterboard so it is above the screed(against touching it). The guy that laid the floor screed said the only reason there is usually a gap between the floor and the plaster is in case the floor gets damp which would then get soaked up by the plaster. He did recommend cutting the excess pasterboard out.

The screed was laid yesterday (friday) and the screed layer said dont walk on it until monday

I am planning on putting in 6inch skirting

 

[Micilin]

Where is the DPM ? This would usually be a heavy guage polythene

 

[delboybully]

The footings people put a base floor in and the DPM is under/in that and came up the sides. It came up against the existing external house wall. On the sides walls the DPM came up and over the base layers of bricks with the wall on the top. On the external wall with the patio door there is the patio doors, a gap and then some bricks sticking up a little, the DPM went over these bricks. These have all been covered by this final screed

The plaster is getting wet from drawing water up from the new screed. They were dry before the screed was added. The screed is about 2.5 inches thick

So do i need to remove any plaster that is touching the screed and also the excessive screed that is above the floor level but under the plaster?

without this excess plaster and screed the plaster wouldnt get wet as it wouldnt be able to draw water from the wet screed

I cant do this until monday as the guy who laid the screed said i couldnt walk on it until then (3 days).

Its ok for the cats after 1 day. So at the moment i have spent many thousands for my cats to have their own personal room!!!!!!!

 

[roughcaster]

I agree with your builder,,, get the plastering done first, and then screed the floor. I would always do it in that order too. As regards to some of the screed being higher than the finished floor level around the edges,, just chip it out, it's only where the end of floor screeders straight edge has pushed the screed mix against the wall.
Everything else he said makes sense, such as "don't walk on the screed for a few days", and "leave a gap between the bottom of the plaster, and the floor screed". The most important thing for you to do is cut away any plasterboard that is lower than the screed, and because you're putting on 6" skirtings, you have plenty of room to play with.
I don't see anything for you to worry about at all,,, but would just repeat,, ""cut back the bottom of any plaster or plasterboard that is touching the floor screed",,, that's very important!!! The excess floor screed around the edges can be left if it is not touching plaster or plasterboard,, or for peace of mind, chip it out.

Cat's wont cause any harm walking over the screed as long as they have slippers on ,,, only kidding,,,, cats will do no harm to your screed now it has set, but it's always advisable to give it a few days to cure before people walk over it.

 

[noseall]

There is no need to chop anything and it is normal for freshly laid screed to wick into anything it is in contact with.

Be patient and let everything dry out.

It is good practice to maintain a gap between the finished floor and the wall plaster. This gap is usually hidden by the skirting board.

However, modern building practices mean that there is little chance of any moisture wicking into the plaster via the floor screed.

 

[ursamajor]

What's going on top of the screed anyway? You'll have to put either a floating timber floor or levelling compound anyway I'd have thought, so don't worry too much if you make a bit of a horlicks chipping that excess screed out.

As for keeping the plaster above the floor, follow the screeder's advice.

 

[roy c]

As the lads have said, but as for putting a floating floor on top of the screed, that should be finished floor level and will now be ready for carpets, tiles, laminates,etc....

 

[ursamajor]

As the lads have said, but as for putting a floating floor on top of the screed, that should be finished floor level and will now be ready for carpets, tiles, laminates,etc....

Did a conversion once which specced underfloor heating embedded under 65mm screed with floating 18mm t&g OSB floor with an oak laminate on top.

 

[delboybully]

Ok so take the plaster out as recommended by the screeder. I think i will also take out the excess screed above the floor level just to be sure to leave a gap between the plaster and screed

I am planning to put in a floating wood floor. Can i lay this on the screed or do i need to put leveling compound on it first?

 

[ursamajor]

Straight onto screed will be fine. What's going on top of these boards?

 

[delboybully]

Straight onto screed will be fine. What's going on top of these boards?

Im confused. I am going to be laying a floating wood floor. Engineered wood

I think i am confusing what i call a floating wood floor and what you mean by boards

At the moment i have this new sub floor. I thought i could just lay the underlay and then the wood floor

From re-reading the answers in this post i have to lay either some wood boards or leveling compound on the floor. If this is the case i would go for leveling compound. Is this hard to lay or should i get a plasterer in to do it? Please bear in mind i am going to have a fishtank with a footprint 6ft x 31in in the room and the floor needs to be exactly level

Also when can this be laid in regard to the sub floor drying out

 

[Micilin]

Ideally your floor should be level, but screeding being what it is, and it the screeder is trying to tie in a few different levels (such as cill of patio door and existing floor for example) it may not be spot on

It may be easier to make sure your floor is just straight, and if it is not level enough over your tank area, it may be easier to level up your tank stand or cabinet than mess about with the floor too much.

Off topic - I'm guessing a marine set up with that size?

 

[roy c]

I thought that a screeded floor was a 50-75mm of screed (4-1 floor mix) put on to the concrete slab and finished to the level of any existing floor level and existing openings so carpets and floor coverings could all be bought through level. As for a "floating floor" I thought that was 20mm T and G (tongue and groove) boards, glued and layed on 50mm polystyrene or kingspan. If that was the case then the sub floor would of been laid to compensate the difference in height, Also if the floor layers were good at their job there shouldn't be any need for self leveller.....

 

[delboybully]

I have checked what i can, cant walk on the floor till monday, using a 4ft spirit level, and although the floor is reasonably level there is some undulations. the difference between the highest and lowest points is about 2-3mm. Does this mean the floor needs leveling compound or will the uderlay and the wood floor take this out

This is the underlay i am planning to use
http://www.woodandbeyond.com/products/Elka-Duo-Underlay-15sqm-Roll.html

In answer to off-topic. Its large freshwater tropical cichlids (about 1ft long). If any of you need advice on cichlids especially oscars come over to oscarfishlover.com where i moderate

 

[ursamajor]

Straight onto screed will be fine. What's going on top of these boards?

Im confused. I am going to be laying a floating wood floor. Engineered wood

I think i am confusing what i call a floating wood floor and what you mean by boards

Got a bit confused myself - was just wondering what you meant by a floating floor since it occurred to me that you might be talking about a laminate or timber t&g

At the moment i have this new sub floor. I thought i could just lay the underlay and then the wood floor

if the floor is level enough then underlay and your boards should be fine.

From re-reading the answers in this post i have to lay either some wood boards or leveling compound on the floor. If this is the case i would go for leveling compound. Is this hard to lay or should i get a plasterer in to do it? Please bear in mind i am going to have a fishtank with a footprint 6ft x 31in in the room and the floor needs to be exactly level

Laying levelling compound is pretty easy, and even though (as I suggest above), may well not be necessary, it does give a pretty perfect final surface to work with.

Also when can this be laid in regard to the sub floor drying out

The thumb rule for wet concrete is about a week per inch of concrete laid, but for damp screed it should be less. Although it's a pest having to wait, you really don't want the subfloor to be sweating under manmade boards.