[chickenboy]

I want to pave some of my paths with slabs, but they are a bit hard to come by in decent numbers.
I have noticed that you can buy a variety of moulds for slabs on the internet, and wondered if it is easy to make your own slabs using these.
What type of cement etc would you use?
What mix ratio?
Other than the moulds, would I need any other equipment?
How long would they take to set?
Would it be worth the effort?

All advice gratefully accepted!!!!!!!!!

[shaun]

the ones you buy are compressed when wet so unless you can do this you will be waisting time and money

[mumofstig]

Years ago, i mean in the 70s, my otherhalf mixed up cement and put it into one of those moulds. It was made sort of, to look like crazy paving  (very fashionable in those days )
and it worked very well. just as strong as laying a concrete path as it was done in situ. Just looked a bit better. We waited for one bit to dry then removed mould and made the next one. seem to remember just mixing enough concrete to do 1 at a time each day after work. We added a little dye to mix and made yellowy ones. missed a few bits of mould pattern out here and there and planted herbs in.
Was the bees knees at the time

[Trillium]

I have one of those molds that I plan to make slabs with this summer. My instructions say to use ready-mix concrete mix, add water and any dye, stir well and carefully fill in the form. The molds are flexible so that you can carefully pull them off when the slab is mostly set. I plan to then flip mine to the good-side up, mist lightly with water and cover with poly for a few days to set hard. If you're concerned about strength, you can set some pre-cut rebar in the middle of the pour.
A 60 lb bag of premix will make about 3 stepping stones, or 7-9 edging stones.
If you take particular care how you handle the forms, you should get well over 12 pours per mold.

[GrannieAnnie]

My Brian used to have a concrete yard and I helped him make slabs and posts etc.  he used to spray a release oil onto the inside of the moulds before pouring in the cement mix to stop them sticking, but you have to be careful not to get too much air into the mix, or the slabs will break easily as they will have too many air holes in them.  We used to have a vibrating table which got all the air bubbles out.

[FCG]

What GA mentions there is quite important - vibrating to get the air out increases the overall strength of the concrete and decreases the amount of liquid it can absorb.

Aggregates are probably better than rebar for laying horizontally on the ground, but don't quote me on that.

[richyrich7]

use an old orbital sander to vibrate the mould    use it on the mould, not in the mix itself 

[Trillium]

I must be missing something Richy; if the mold is sitting under the wet concrete mix, how would you use the orbital sander to vibrate out the air?

[richyrich7]

I must be missing something Richy; if the mold is sitting under the wet concrete mix, how would you use the orbital sander to vibrate out the air?

if you making them on a bench you can use the sander to vibrate the bench, I've seen one where they'd actually screwed the thing to the underneath of the bench 

or if the molds got tall enough sides you can apply it to the edges, as long as it makes reasonable contact it should work.

[chickenboy]

Thats actually not a bad idea Richy!!  Thanks guys.  Will let you know how I get on.

[woodburner]

Don't know why I didn't think of searching the internet sooner for a suitable mould, but actually having tried, I'm not having much luck

All I want are a few (actual number dependant on price) 1ft sqare or wide moulds.

I keep finding machinery for mass production 

[mumofstig]

Googled  'DIY paving moulds' and came up with a load and there are a few on e bay if you enter 'paving mould'.................or are they not what you wanted?

[Trillium]

Here's a link to the decorative square slabs I'm making for a pathway through the grassy areas. I'm doing the Celtic design.

http://www.leevalley.com/garden/page.aspx?c=2&p=53312&cat=2,2180,33222&ap=1

[mumofstig]

Try here quite a choice

http://www.bibba.co.uk/2032-paving-mould-1.html

[GrannieAnnie]

Shame we sold all ours!  I could have sent you one!!!!