mixing a dry mix of cement in a mixer

happyhero

HI I am putting in some posts to build a fence and was told the best way was to use a totally dry 6:1 mix and then poor 1/2 a bucket of water on the cement when the I have compacted it around the post and it is holding it in place. They said this was a very popular method with fence installers as apposed to a wet mix where the posts needed much more support before the cement goes off.

Anyway what I would like to know is if I can mix this dry mix in a cement mixer as I have one that I have hardly ever used, given to me by my father. Will it mix ok in a cement mixer without water and will it poor out or will it just clog up as a unmixed mess in the mixer?

Obviously a lot easier with the mixer if it works.

Any help appreciated.

yan1

That method is great for fencers working on per metre rates, it's so much quicker. But...... It cannot be guaranteed all of the ballast and cement will bond and therefore harden. the water acts as the catalyst in mixing of cement process. Do it in the mixer in following order- bit of water to moisten the drum, 5 shovels of mixed ballast, bit more water ( should still 'look' dry i.e not liquid form) add half a bag of cement then 5 more shovels of ballast. let it mix thoroughly and add water a little at a time until it is still rattling in the drum but if you take a handful out it will just about bond together in a ball.
Definately mix it drier rather wetter because also too much water can weaken the concrete in the drying process.

Hope this makes sense, others opinions will vary but this is my proven method with no call backs in many years.

owls

Ive never heard anything as daft i think someones leading you down the garden path.:rotfl:

for a start you should be mixing concrete, not morter

mix it at 2.1.1.1 sand, cement, limestone dust, gravel .just depends on the size of posts

to level the post up, pack the botom of the trench with large hardcore such as bricks then add the concrete,compact it down around the post with a lump of timber such as 3 by two it should not move as you wedged the bottom of the post with brick/rocks etc set a string line up from your first post to the last to keep them all in sync and your away.

dickieg

I did the FILs fence with the help of a mate, we mixed the dry mixture 3 sand + gravel to 1 cement in the mixer, compacted around base of post, levelled off with soil and then dampened with watering can of water, the fence was put up over 2 years ago and is as solid now as then. I didnt think this would work, but apparently the dampness of the surrounding soil is adaquate. I had started off by mixing wet compo but it was to much hassle wedging the posts to keep them in the same position. Then as i say my mate (who as done this sort of thing before) suggested the dry mix, all i can say is worked for us

27col

If you use the bag mix sold for fence post installation, the instructions say to use it in a dry state and to add water afterwards. I did a few posts recently and it seems to work ok. I have never tried using a dry mix that I mixed myself. The bag mix does not look like the same stuff that you mix yourself.

tomsolomon

The best thing to use is postcrete. But if your mixing it yourself, I used to use 421 or 621 depending on the soil thats four or six sand, two gravel, one cement. Add just a little water to bind it. Do not soak it. If the mix is too wet the post will move.
Add a little of the mix to the bottom of the hole to get the desired level for the post, then pack the rest around the post stopping just short of the ground level and tamp down with a piece of 3x2.
PS. Yes it will mix in a mixer.

Fire_Fox

Many years ago I laid my own patio, my only broadly similar experience being tiling a bathroom. Figured gravity was more on my side so ordered the materials and took a week off work ... I ended up dry mixing my sand and cement in a washing up bowl; my builder thought it was hilarious but admitted I did a good job.