Am i bodging?

[specialbranch]

Im trying to up the efficiency of my jobs and have recently laid a couple of Indian stone patios on ready mixed mortar
I can get 5 tubs of 3:1 building sand and cement with a glug of sbr in delivered to site at £25 a tub. It keeps the site loads neater and saves me having a labourer on the mixer all day. I lay on a full bed with sbr painted on the flag. What im really asking is, why is grit sand used over building sand and do you think im likely to have any issues with this laying method?
Cheers Chris

[GB_Groundworks]

Because it has a large grain size so much improved interlock it is not recommended to lay paving on bricklaying mortar, how much efficiency will you have saved when they've all failed come first heavy frost?

I take it they don't deliver a paving mix with sharp/grit sand?

[specialbranch]

Yep fair do's I didnt think the particle size of the sand would make such a big diffrrence, I thought at 3:1 the cement content would make it pretty bullet proof. I can easily get hold of grit sand mix but it comes semi dry so would need to go in the mixer to wet up so not saving anything as I like to lay on a wet mix. Back to mixing on site then!

[Carberry]

Grit sand is best choice but I don't think using 3:1 building sand would ruin your paving. If it is a lot cheaper than hiring a guy to spend all day on the mixer, you have so much work on that you need to bang through a few jobs quicker then go for it or you're running over schedule then go for it.

[haggistini]

Local site flogging a few tubs eh!! I lay all my paving on semi dry and if its thin units then a few gulps of SBR cement slurry before bedding ..I have photos of building sand and cement bedding on 100mm slabs 100mm bed and epic fail come on special knock it up!!!

[specialbranch]

Cheers Haggi, I cant work on semi dry, Feel as though im battling to get adhesion to the flag(sbr slurry etc) all the time when a wet mix is would do it.. I like a building gobbo consistency which led me to using this mix. I can go collect tubs of 3:1 grit sand mix to the consistancy I want but they wont deliver to site. That might be the answer its a 45 min round trip from my yard but they open early so I can be there and back before my lads are out of bed:D

[local patios and driveway]

Same, i use semi dry with a cement slurry. Bullet proof.

Have you ever took up a patio on building sand? Easy peasy

[cookiewales]

Cheers Haggi, I cant work on semi dry, Feel as though im battling to get adhesion to the flag(sbr slurry etc) all the time when a wet mix is would do it.. I like a building gobbo consistency which led me to using this mix. I can go collect tubs of 3:1 grit sand mix to the consistancy I want but they wont deliver to site. That might be the answer its a 45 min round trip from my yard but they open early so I can be there and back before my lads are out of bed:D

hi cpi are close to you they have small silos hold 8 ton or around that i was paying £65 ton 4/1 no charge for silo easy clean after using they do a 240 motor as long as it has 32 amp breaker fitted cheers cookie

[GB_Groundworks]

8 tons is a lot for most domestic jobs though

[lutonlagerlout]

grit/flooring sand all the way here
building sand just isnt strong enough
I have seen it down and its not right

semi wet here for indian stone
dry for council greys
LLL

[TheRockConcreting]

why is grit sand used over building sand and do you think im likely to have any issues with this laying method?
Cheers Chris

In the concreting industry we don't use building sand in the mix because it has a high clay/slit content resulting in a very weak mix.

when we use a 0/2 sand in concrete it has to me within 6-7% clay/slit quarried wasted is fine for this.

(a good test for this is to get a large glass jar fill with sand to halfway, then add water fully covering the sand, making sure the water level is slightly higher than the level of sand. put the lid on shake well leave it to rest for a few hours you will see all the clay and slit sitting on top of the sand, measure with a tape and workout the percentage of slit.)

standard concrete uses quarried 0/4 washed because the larger partials help lower the slit content and give the mix a better grading.

[r896neo]

I get a local readymix lot to deliver screed mix, so a 5:1 but with a good drop of plasticiser and mix up to bricklaying consistancy.

It is cracking as a time saver and much cheaper. It was 100+Vat for 1 cube and the materials to make a cube would be maybe 70 quid anyway. easy choice.

They will only do a minimum of 1 cube though as they obviously have to mix it up specially.

[cookiewales]

8 tons is a lot for most domestic jobs though

no you keep using on all your jobs they dont charge for silo

[Tony McC]

(a good test for this is to get a large glass jar fill with sand to halfway, then add water fully covering the sand, making sure the water level is slightly higher than the level of sand. put the lid on shake well leave it to rest for a few hours you will see all the clay and slit sitting on top of the sand, measure with a tape and workout the percentage of slit.)

There's a photie of this being done....somewhere on the site, but can I find it? C I F!