Sand and Cement Plastering

I did a lot of research before I started this project and I seen many posts with plasterers advising you can use sand and cement for base coats. I had to take all the plaster from each wall in my house because it was all blown it was falling off the walls and turning to dust.

I PVA'd the brick before I put my first coat on, everything dried ok, solid a few days later. I have been using the same mix throughout a 4:1 with plasticiser.

I chose to us Sand and Cement as it was a lot cheaper and in theory lot more stronger than normal plaster (hardwall or tough wall).

I noticed this evening that there was some cracking and hollowness on he last layers which I have not seen before also the mix look a different colour.

I have not changed my ratios was using blue circle multi-purpose cement but I changed over to ecocem, I am not sure if the ecocem is not as good as the blue circle.


Everytime I create a mix I keep a sample to one side and see how it is dried, the last batch for some reason was just like mud dried mud. I think I am answering my own question here and maybe the ecocem is not as good as the blue circle but I can't see how this is so surely all cement have to be a certain standard to be cement?

Any advice and tips would be most welcome.
 
I did a lot of research before I started this project and I seen many posts with plasterers advising you can use sand and cement for base coats. I had to take all the plaster from each wall in my house because it was all blown it was falling off the walls and turning to dust.

I PVA'd the brick before I put my first coat on, everything dried ok, solid a few days later. I have been using the same mix throughout a 4:1 with plasticiser.

I chose to us Sand and Cement as it was a lot cheaper and in theory lot more stronger than normal plaster (hardwall or tough wall).

I noticed this evening that there was some cracking and hollowness on he last layers which I have not seen before also the mix look a different colour.

I have not changed my ratios was using blue circle multi-purpose cement but I changed over to ecocem, I am not sure if the ecocem is not as good as the blue circle.


Everytime I create a mix I keep a sample to one side and see how it is dried, the last batch for some reason was just like mud dried mud. I think I am answering my own question here and maybe the ecocem is not as good as the blue circle but I can't see how this is so surely all cement have to be a certain standard to be cement?

Any advice and tips would be most welcome.

I forgot to mention that I was using being huge soft building sand and coming to think of it I got a bulk delivery of red sand I think the problems started there. I was noticing lumps of red sand in my mix which I had never seen before I thought it was quite strange.

I have a gut feeling I might have to take off the last few layers and start again
 

Havagojo

Active Member
I forgot to mention that I was using being huge soft building sand and coming to think of it I got a bulk delivery of red sand I think the problems started there. I was noticing lumps of red sand in my mix which I had never seen before I thought it was quite strange.

I have a gut feeling I might have to take off the last few layers and start again
Your gut feeling may be right
I wouldn't PVA the brick ,just raked for physical fix, brushed clean and dampen used some lime in a weaker mix (and weaker than that for second coat) and only plaster with clean Sharpe , not soft or red
Each to their own
 
Your gut feeling may be right
I wouldn't PVA the brick ,just raked for physical fix, brushed clean and dampen used some lime in a weaker mix (and weaker than that for second coat) and only plaster with clean Sharpe , not soft or red
Each to their own

Hi thanks for the reply, the previous coats I was using where Diall Building sand which seem consistently fine, but this bulk stuff so different , should I got back to the Diall sand ?
 

Stevieo

Royal Spin Doctor
Hi thanks for the reply, the previous coats I was using where Diall Building sand which seem consistently fine, but this bulk stuff so different , should I got back to the Diall sand ?
If it was my house, I'd be board it out with insulation boards, f**k s&c
 

Havagojo

Active Member
Hi thanks for the reply, the previous coats I was using where Diall Building sand which seem consistently fine, but this bulk stuff so different , should I got back to the Diall sand ?
The bagged sharpe diall sand is good and consistent although expensive , lucky I'm in Bedfordshire and get good Sharpe by the lorry , £30/t
Its important the second coat should be a weaker mix ( more sand )
Soft sand is for brickwork as far as I am concerned ( and builders who can put a bit on)
 

Dacha

Member
@Do_It _With_Dave
Hats off for trying.
By the time you apply couple of layers, hack off a couple of layers, it will become expensive and dusty.
Cement/sand can be brittle, may need certain conditions while drying. Plus it takes long time to set fully.
Cement/sand/lime mix is more forgiving, and readily available as premixed.
 

Havagojo

Active Member
If you have cavity filled walls stick with sand and cement ( and lime for me ) , thermal boards are very expensive , you loose a lot of room including the dabs , its only 9.5mm board ( double scrim , the taper fill and first coat ) , enjoy future shelf and heavy wall
 

Dacha

Member
Depend if you go for insulation or just a finish. Insulation will create added thermal comfort, and take a bit of room.
 

Dacha

Member
Good insulating render with low U value is very expensive to buy and install. Couple centimeters thick.
In cases where insulation cant be installed on outer side of wall.
 

Havagojo

Active Member
Good insulating render with low U value is very expensive to buy and install. Couple centimeters thick.
In cases where insulation cant be installed on outer side of wall.
Wear thermals is the cheapest, quickest solution, or stay in bed with the missus
 

Andy g

Well-Known Member
Plastering san
I did a lot of research before I started this project and I seen many posts with plasterers advising you can use sand and cement for base coats. I had to take all the plaster from each wall in my house because it was all blown it was falling off the walls and turning to dust.

I PVA'd the brick before I put my first coat on, everything dried ok, solid a few days later. I have been using the same mix throughout a 4:1 with plasticiser.

I chose to us Sand and Cement as it was a lot cheaper and in theory lot more stronger than normal plaster (hardwall or tough wall).

I noticed this evening that there was some cracking and hollowness on he last layers which I have not seen before also the mix look a different colour.

I have not changed my ratios was using blue circle multi-purpose cement but I changed over to ecocem, I am not sure if the ecocem is not as good as the blue circle.


Everytime I create a mix I keep a sample to one side and see how it is dried, the last batch for some reason was just like mud dried mud. I think I am answering my own question here and maybe the ecocem is not as good as the blue circle but I can't see how this is so surely all cement have to be a certain standard to be cement?

Any advice and tips would be most welcome.
Plastering sand is the best
 

Stevieo

Royal Spin Doctor
A

Half a pint of fairy
Oh don't....fekkin lab did that to me once. He was old too, so I thought he'd have more sense. All the cement was like ....fcuk, I dunno ...like a sponge and it all slid off my trowel, but there was no more cement and no money so the wall got built anyway - rendered over it quick.
 
I spoke to the people today you think it's the sand that has caused this problem, I purchased a good few bags of Diall soft sand again.

It is a picture of two of the walls the layers behind ash and cement where the sand was from teadepoint Dialling.

I have had many sand and cement repair jobs in this house and I have never seen the mixture so bad until I use this new building sand in bulk which is orange from a local yard.

I managed to take all the plaster off with one hand and the bolster that is how bad it is.
 

Attachments

Stevieo

Royal Spin Doctor
I spoke to the people today you think it's the sand that has caused this problem, I purchased a good few bags of Diall soft sand again.

It is a picture of two of the walls the layers behind ash and cement where the sand was from teadepoint Dialling.

I have had many sand and cement repair jobs in this house and I have never seen the mixture so bad until I use this new building sand in bulk which is orange from a local yard.

I managed to take all the plaster off with one hand and the bolster that is how bad it is.
Just to be clear - you put the top coat on and the substrate exposed in the pic is the original, right?

I don't see any key in the wall....
 
Just to be clear - you put the top coat on and the substrate exposed in the pic is the original, right?

I don't see any key in the wall....

The key is there, its filled in with this top layer, there has been 4 layers up to now, it is only this last layer that it crumbling,
 
@Do_It _With_Dave
Once sand and cement is all nicely finished, are you going to plaster over it or brush on some limewash paint ?
IF i can get it level/straight I will attempt the last layer with multi finish, I am just building the base layers out first to get back the depth I original had as I have a lot of cable in the walls as this is a smart home I am doing.
 
Top