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Posted: Sun Jul 12, 2015 8:23 pm
by timstanley1985
Hi,

I recently laid a 25m2 patio using 22mm Indian sandstone flags. A random pattern of 1x1s, 1x2s, 2x2s and 2x3s. I didn't do the greatest job keeping them level but given I did the job for a grand all in I'm happy enough.

Having laid the last slab a fortnight ago I have realised I may have made a huge mistake. I spread 4 ton of sub base to about 50mm and compacted - so far so good. When it came to sticking the flags down, having spent hours on this site I decided to lay them on a full bed of mortar, starting at about 50mm depth and increasing to 100mm on the lower side of the site. The problem is when I read "mortar" I went out and bought 4 ton of builders/soft sand and laid the patio on a mix of 6:1. I then pointed with a 4:1 mix.

Should I be worried as I understand now I should have used sharp sand? or be even planning to relay the patio in a few years time? Or is it likely to be fine, it is only a back garden patio used for a table and chairs etc.

The thought of having to re-lay the thing fills me with dread so I hope it will be OK!! Any advice would be greatly appreciated

Posted: Sun Jul 12, 2015 8:59 pm
by r896neo
100mm bed of building sand mortar must have been horrible.

In reality i would imagine you wont have any problems. You may get more efflouresence than normal but many patios are laid on a lot more rubbish than yours and fare ok for 10 years.

No point fretting about it now.

Posted: Tue Jul 14, 2015 12:40 pm
by Tony McC
The other risk is that, with building sand usually having a relatively high iron content (hence the red/orange colouring) there's a greater risk of capillary staining if you've used pale coloured flags such as <spit> Fossil Mint.