How much sand & cement do I need?

Question

...to rebuild a garden wall 20m long 2ft 6in high and 2 bricks thick?

Answer 1

You've recd many different answers here that will leave you a trifle confused. I'm old and practical and don't mess about with cake mixtures. You don't indicate whether you've caculated the number of bricks you need, but here's a simple way to work it out:- 4 bricks to a yard in length, 4 bricks to a foot in height. eg., 66 foot long = 22 x 4 = 88.
2' 6" high = 2 1/2 x 4 = 10
Thus 88 x 10 = 880 bricks NOW, It isn't really necessary to have a low brick wall two bricks thick . . . you could have one brick thick with piers at intervals to give stability and also use single coping on top. But if you're set on 2 thick then it will be "880 x 2 = 1760 bricks, get at least 1800 though!
If I were you, I'd consider getting the sand and cement in two or three lots because of space problems and the cement getting damp. You'll never get a situation where you have the exact quantity you actualy need. If space/storage is not a problem get a tonne bag of "soft" building sand and ten bags of cement and get more as required when you'll be able to judge it better.
As someone has said get a tin of mortarciser/plasticiser and use per instructions.
Whichever way you do it don't flood the mix with excess water; it needs to be spreadable from the trowell.

A good cement mix for an outside wall is 5 to 1 ie., 5 buckets soft sand to 1 bucket cement. Maintain this mix throughout otherwise you'll have colour variations for starters.

Answer 2

Lets convert your measurements :-

1) 20m is 89 bricks long.
2) 2ft 6in is 750mm which is 10 bricks high.

A brick is 215mm long. If the thickness of your wall is 215mm, which is 2 bricks side-by-side with a 10mm gap, then it's classed as a 1 brick wall.

89 x 10 is 890 x 2 = 1780 bricks.

Each brick takes 1kg of mortar. Order 2 dumpy bags and 10 x 25kg bags of cement (OPC).

Bricks at/below ground level, 3 parts sand to 1 part cement.
Rest can be 4 parts sand to 1 part cement.
Use a buket to gauge.

Put a 10mm expansion gap in at every 5m to 6m. So make the wall up in 18 5m lengths. Use debonding wall ties at expansion gaps.

Build the wall where the top of the foundation concrete is approx 400mm below the surface of the ground. This is a concrete block and a brick. You may need to consider these and be prepared to order some small bags of sand and an extra bag or two of cement.

Unless you can do best part of 1000 bricks a day, don't go for premix mortar.

You could put 1 part lime in to increase workability of the mortar or febmix.

Don't forget mortar for fixing any cappings to the top of the wall. If you did brick on edge, you would need 120 bricks.

Answer 3

there are many different size brick to choose from, but let's assume you're using standard 4x2-2/3x8 brick (this is a nominal dimension which includes the unit plus the joint thickness)you need 675 brick for each 100 square feet of wall surface(that's only one side)
for the mortar, you'll need just over 8 cubic feet of mortar per thousand brick.
for one cubic foot of type N mortar the ratio by volume is 1:1:6 that's 1 part portland cement: 1 part hydrated lime : 6 parts masonry sand
those are by volume. the amounts by weight are,15.67 lbs cement: 6.67 lbs lime: 80 lbs sand. per cu. ft. of mortar
i hope this helps.
i think the people telling you a one to three ratio are refering to pre-packaged mortar mix, not cement. in which case they are correct

Answer 4

mix is 1:6 cement/sand and use plasticiser to make it workable, in the old days a drop of washing up liquid was used as a plasticiser. do a dry run first and place out the bricks, measure twice, build once

Answer 5

one part cement, three parts sand. If you are working with brick, you will want a really find sand, not a course play sand.

Answer 6

get a cement merchant to supply you with 2 buckets/tubs of 36 hour mortar. make sure you keep it covered when not in use to stop it turning to pi'ss. if you have no access get a wheel barrow and hump it from the buckets. btw a tub/bucket from a cement works is about 2ft by 3ft by 2ft in dimension at a guess just under a ton when filled with mortar.

Answer 7

Without doing the math for you, I see valid suggestions from others to actually connect with a company that will sell what you need, and perhaps even deliver it to your site.

My question would be however, why not get premixed?

Steven Wolf

Answer 8

One cement and three of sand.

Answer 9

big bricks or small ones?

Answer 10

If you ask at the builders mrerchants they will advise you.