Page 1 of 1
Posted: Tue Jul 06, 2010 1:15 pm
by Mcgovern
I've just bought a Bradstone Natural Stone patio pack (Autumn Green). Having read a few of the threads on here, I'm a little concerned about the 22mm thickness - particularly for the 900mm x 600mm flags.
The ground the patio's going on is pretty solid clay. In order to lay the flags, will a compacted 50mm layer of MOT Type 1 and a 25mm full mortar bed be sufficient? Or does this need to be 50mm?
Also for the mortar bed, I'm looking at a 6:1 wet (ish) mix. Am I right in assuming that a dry mix for this type of stone isn't suitable?
Cheers.
Posted: Tue Jul 06, 2010 9:24 pm
by mike builder/landscaper
25mm is a bit tight for bedding, i would definetly go for 50mm, they bed down a lot easier. also go for 5/1 mix with a little plasticiser.
Posted: Tue Jul 06, 2010 9:52 pm
by Bob_A
I done my own paving which is also 22mm. I'm not an expert so don't take this as gospel but..........
From my understanding of the main site the mot needs to be a minimum of 75mm. (twice the thickness of the largest particles)
http://www.pavingexpert.com/faq_subbase.htm#depth
My mortar bed was about 40mm and was a wettish 8:1 mix with some pva and plasticiser added.
Just be careful with the 900x600's.
Check them for hairline cracks before you start. Out of 65sq/metres I did get a couple like that, they sounded hollow so I tapped them before I started to lay them and they broke!
Wasn't a problem as I was sent replacements free of charge. I kept the old ones and used them for offcuts.
Treat the 900x600 with respect. Get the bedding layer as best as you can so you can tap them down into consolidation rather than bashing them.
Posted: Wed Jul 07, 2010 8:18 pm
by Mcgovern
Thanks guys. I'll aim for a 50mm bed for both, as I suspect I'll probably shave off too much clay and end up with around 75mm for the sub-base.
Thanks for the advice about the hairline cracks. I'll make sure I give them a thorough checking! I suppose it makes sense that if they're only 22mm thick they're bound to get some damage in the crate.
I'll let you know how I get on.
Incidentally, I've seen a few threads about using linofin to seal the surface of the flags - do they stain easily?
Cheers.
Posted: Wed Jul 07, 2010 8:31 pm
by Mikey_C
if you are laying on to clay i really would recommend at least 100mm of type 1.
Posted: Thu Jul 08, 2010 12:55 pm
by London Stone Paving
R.E Sealing slabs
The paving you have purchased is either Raj Green or Autumn Brown. Both are Indian sandstones originating from the Kota region and both are hardwearing stones. Unless you have a particular concern (i.e oil, grease stains) then these stones dont NEED to be sealed.
However sealing is sometimes done for aesthetic reasons to, in particular to enhance the colour of the stone.
I always think that one of the beauties of natural stone is the colour change through the seasons, something which will be drastically reduced by sealing. This is just personal preference btw.
If you are thinking about sealing do a test on an off cut first.