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Nov 1, 2011

Top Ten Tips for Laying Concrete


There's no need to be intimidated by laying concrete - it's an easy material to work with and incredibly versatile. The only thing to remember is that it's difficult to fix mistakes after you've made them, so always plan carefully before you start. Our top ten tips should help you get a great result.

1. Don't lay new concrete over old concrete
Laying new concrete over old concrete will lead to only one thing - cracks. Before laying new concrete you must completely break up the old concrete and compact the surface.
2. Always use clean sand and gravel
Don't try to save money by scraping up some gravel from your old driveway or pinching a bit of sand from the beach - always buy clean products from your local building product supplier. Even small amounts of foreign matter can ruin an entire batch of concrete.
3. Be stingy with water
Too much water in your mix will weaken your concrete, causing it to shrink as it hardens. See the tip below about judging when your mix is right - and remember it's easier to add more water if you need it than it is to take it away.
4. Concrete can burn
Concrete mix can actually burn your skin if it comes into contact with it, so dress sensibly with long sleeves and long pants and wear gloves as well as strong boots and safety goggles.
5. Judging a workable mix
A good concrete mix should be dull in appearance - a 'shine' to your mix probably means that there is too much water in the mix. To judge whether your mix is too wet or too dry, draw a shovel tip over the top of the mix to leave a series of ridges. If the ridges crumble, then your mix is too dry and if they settle back into the mix then it is too wet.
6. Don't mix concrete on the ground!
It might seem obvious, but it isn't to some people...if you are mixing your concrete by hand, never mix concrete directly on the ground. Put down a sheet of hardboard, plywood or tough polythene sheeting first. Mix your concrete close to where you want to use it so you don't have to transport it too far.
7. Make sure the surface is level
After you have poured your concrete into the formwork and you think it is finally level...it may not be. Tap the outside of the formwork with a hammer - this will expel any air bubbles and the concrete will settle again. Fill up any hollows and level again.
8. Create a non-slip surface on outside surfaces
A smooth finish on concrete can be very slippery. To create a simple non-slip surface, after you have tamped your concrete, simply draw a stiff bristled broom across the surface of your concrete to create a slightly ridged finish. Ideal for driveways and paths.
9. Concrete needs water to cure
'Curing' simply means the process of concrete drying and hardening. If concrete dries too fast it can crack, so keep your newly-laid concrete covered and moist for at least seven days to cure properly.
10. Concrete takes longer to cure in cold weather
When the weather is cold concrete needs longer to cure - be patient and you will get a better result.

Article Source: EzineArticles.com

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