Raised patio with sleepers

kevjacko · Post: # 110197Post **kevjacko** Mon Jul 18, 2016 8:38 pm

OK here goes again. Good site this excellent advice with projects so far.
I am going to build a 25mt square patio. I am using sleepers for the edges broad side up. I am going to put a layer of rubble down whack it, then a layer of MOT, leaving enough for a a layer of grit sand, the flags (riven) will go last and lie flush with the top of the sleepers.
Question is, am I ok just laying on the grit sand then jointing in, seeing as the flags will be contained by the sleepers, or do I need to lay them on a full bed of mortar, in which case I would do away with the grit sand.
Cheers

r896neo · Post: # 110202Post **r896neo** Mon Jul 18, 2016 9:09 pm

Small flags 400x400 or smaller can be laid on just grit sand but it will never be a top job and will start to deteriorate in 10-15 years. Plus you can only joint them with kiln dried sand as they reamin slightly flexible on sand bedding.

Flag laid on and pointed with mortar can last a lifetime and will be low maintenance for many years.

Do it right do it once.

kevjacko · Post: # 110207Post **kevjacko** Mon Jul 18, 2016 10:11 pm

r896neo wrote:Small flags 400x400 or smaller can be laid on just grit sand but it will never be a top job and will start to deteriorate in 10-15 years. Plus you can only joint them with kiln dried sand as they reamin slightly flexible on sand bedding.

Flag laid on and pointed with mortar can last a lifetime and will be low maintenance for many years.

Do it right do it once.

Thanks for reply, I had a feeling that might be what came back. The sleepers are 9 inches deep approx 230 mm. I'm thinking of 100mm hard core, 75mm MOT, 35 mm cement (1 part cement 4 parts grit sand) the remainder is the depth of the flag.
Will I need to dig any deeper than the depth of the sleepers which I am going to lay on a bed of launched concrete.
Also the patio is not joined on to any property. Will I still need a slight fall for drainage?

sy76uk · Post: # 110209Post **sy76uk** Mon Jul 18, 2016 10:17 pm

Paving should always have a fall to keep the water moving. If it doesn't it will green up very quickly.
The rest of your plan is sound.

Post: # 110213Post **Tony McC** Tue Jul 19, 2016 10:19 am

Bear in mind that wooden sleepers expand and contract with moisture content so the joint between them and the rigid paving is best filled with summat like kiln dried sand as a rigid joint will just crack.

kevjacko · Post: # 110221Post **kevjacko** Tue Jul 19, 2016 4:17 pm

sy76uk wrote:Paving should always have a fall to keep the water moving. If it doesn't it will green up very quickly.
The rest of your plan is sound.

Thanks for that Sam, kinda figured as much. I'll probably look at a couple of inches over 5 meters approx.

kevjacko · Post: # 110222Post **kevjacko** Tue Jul 19, 2016 4:21 pm

Tony McC wrote:Bear in mind that wooden sleepers expand and contract with moisture content so the joint between them and the rigid paving is best filled with summat like kiln dried sand as a rigid joint will just crack.

That's a cracking tip, something I would probably have missed. Cheers. I'll leave a border gap tween sleepers and slabs of 10mm and fill with kiln dried.
Cheers