Forum: Site Works
Topic: Base for artifical turf?
started by: andyste1
Posted by andyste1 on 12 Mar. 2019,14:23I've read many different "guides" to installing artificial turf, so was after some thoughts here. The most common approach seems to be a crushed limestone sub-base topped with 35mm of sharp sand, but several articles mention long-term issues like the sand washing away, ant burrowing, etc..
What is the purpose of the sand layer - is it just used to create a level base or does it also help with drainage? What are the risks to laying the turf straight on the crushed limestone?
I'm also curious to know how permeable crushed limestone is after compacting. The lawn has no slope, and would be surrounded by a combination of brick and sleeper edging, so how can I avoid standing water after heavy rain?
Bonus question: on a practical level, would I install the brick edging first, then add the sub-base and compact? Just concerned about wrecking the edging, having not used a wacker plate before!
Posted by Tony McC on 19 Mar. 2019,16:58Have you read < this page? >
The sand is an *essential* regulating and cushioning layer.
The sub-base is reasonably permeable, even if it's DTp1 rather than, say, DTp3
I did my own lawn a few yewars back (as shown on thet page) and it has never yet flooded or even so much as gone soggy.
Ants and other burrowers can be an arse-pain, but nothing too serious. Weeds growing *into* the placky-grass are more of a problem. You'll need to treat with weedkiller or biocide once a year at least. The biocide (I use Wet & Forget) seems to have deterred the occasional worm and a few beetles that had previously tried to make a nuisance of themselves, as well as prevent any grass/weed germination.
And, as you will see, I put the edge course in first.....I always do with paving, so I did the same for placky grass....then scraped back as required to accommodate the bedding concrete. Once haunched and hardened, I topped up the sub-base, compacted, placed the sand, screeded and compacted that, and never so much as nudged the edge course.
Posted by andyste1 on 11 April 2019,14:50
Apologies, I hadn't realised there was a dedicated page. Too much useful info on the site and a case of can't find the wood for the trees!
Anyway, one more question - your page makes no mention of anchoring the turf to the edging (e.g. a concrete haunch to glue the turf edge to). Did you do this or are you just relying on the weight of the brushed-in sand to keep everything in place? Surely this wouldn't be enough?
Posted by Tony McC on 12 April 2019,12:27On my own project, which is microscopic in scale if truth be told, I decided not to waste time and money on anchors, but I know the more clued-up installers laying placky grass to larger areas do like to use them at seams and at edges.
Mine's been down about 4 years now and it does tend to curl-up a teeny bit at loose edges. Not enough to be a problem, but enough for my highly-critical eye to notice. If it did ever curl-up enough for, say, one of the grandkids to get their grubby little paw beneath and lift it up, I;d look at retro-fitting anchors and/or glueing down those edges.
Posted by Forestboy1978 on 13 April 2019,10:43Aquaflow is an expensive but nice medium to work with as a base.
Dry postcrete perimeter so you can whack 4 inch galvanised nails in every 6 inches. Don't put too much postcrete or you'll need to drill the holes before you nail which is a bugger. You want just enough that nails need to be hammered with a bit of force. This is another reason why aquaflow is superior to limestone type 1 MOT because the particulates are smaller and they don't stop nails going through postcrete in base with big chunks of limestone.
I don't see how an inch and a half of grit sand, over any length of time is going to embed itself fully into 3 inches of sub base to the point it's not providing cushoning any longer. Unless you don't have a textile membrane underneath of course.