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Posted: Mon Aug 15, 2011 9:36 pm
by iHyde
First time DIY on a front walkway at my cottage home and I have a couple of questions. This is going to be flexible construction using tumbled Indian sandstone square setts.
Background: The walkway is curving with a 100mm tall x 180mm wide concrete, exposed aggregate, eased-edged kerb with inset cobbles and pebbles, with single rebar, expansion cuts every 2.5 meters and haunched (I may also lightly acid-stain it, can't decide yet). The walkway is about 1.2 meters at its narrowest point (within kerbing).
The sub-base is 100mm of 25mm- crushed with 6 years of settle topped with 100mm of 16mm- crushed compacted with 4 passes of plate compactor. There is a 1.5 degree camber in the sub-base which will be transferred up through the bedding to the walkway (about 12mm from center to side). The sharp-sand bedding will placed, compacted with one pass of plate compactor, and screed with trammel bars to 22mm below finished grade (allowing for roughly 10mm proud sett placement to be leveled out with plate compactor).
The setts are tumbled Indian sandstone roughly 140mm square but, and here's the rub, they vary in thickness from 30mm to 50mm in thickness with the majority in the 40mm range. (Yes I know but someone made me an offer on these I couldn't refuse).
Do you have any tips for laying these setts? Does the screed depth sound about right? Any methods or tools you use to remove or add sand for each sett as it is laid? Keep a bucket handy, eh? Should I tap them lightly after setting them at about the right height? Rubber mallet or small deadblow hammer?
Also, as you can see from the rough layout I was playing around with here (without the sand in place yet), the curves in the kerbing present some challenges since I want to also curve the setts across the walkway's width and vary the angle of that curve slightly, especially at the bottom of the walkway where it flairs out and bends (top of the photo). From what I can see, if I cut progressively more aggressive wedges across the horizontal sett edges, starting at the midpoint of course 4 from the top, and lay those to the right of midpoint on the next 4 courses that should correct for both the radius and the slight change in the course's orientation by the time I reach the "straighter" part of the pathway.
Does that sound about right?
The walkway widens out to about 6 meters x 2 meter patio (with nary a straight edge) in front of the house. If I was more ambitious I might try bogens at that point since I already have a curve going but I know I'm already ambitious enough on this project, and I'm not sure I want to do that much cutting.
Thank you for any ideas, insights you may be able to provide. This is an amazing website and forum, I've done much reading here. Completely invaluable and huge respect for the work I've seen here.
Posted: Mon Aug 15, 2011 10:07 pm
by Pablo
Hi there firstly my Brother lives in Issaquah and I was hoping to visit him soon if you were to fly me out there first class I'd lay your paving free of charge. 
With regards your method of laying, small setts like these need to be individually bedded on a 6:1 slighly wet sand and cement mix if you lay them on a flexible bed then the thinner ones will kick out and also all the pointing will fail. You can lay setts on a flexible base but they need to be calibrated on all sides so they are uniform. I'd love to see some more pictures of your garden you've got some lovely plants and the exposed aggregate sounds interesting.
Paul.
Posted: Tue Aug 16, 2011 4:45 am
by iHyde
Issaquah is nice. Wish I could afford the ticket, I'd do it 
) I should mention I live out on the Olympic Peninsula and we get about 3 meters of rain between Oct. and May so I was a bit concerned about drainage and rigid construction but this has a good slope.
Okay, that makes sense on the bedding material. Should be able to do that in a windrow style of laying I'm thinking, tapping them in one at a time, checking the camber with a plywood profile, then partially fill joints as I go with the bedding material and wet them in. Will that provide enough bed compaction though? Since this is a cottage garden path up to the house I don't want it to be too formal. Can I finish pointing with just straight kiln-dried pointing sand?
Thanks for the help. I'll try to get some more pics up. Built the house myself and the front yard garden is a work in progress. Herbs and perennials on one side, vegetable on the other, native dry-laid river rock border. Plan to extend the river rock wall out and in places slightly over the curbing.
Posted: Tue Aug 16, 2011 7:38 am
by lutonlagerlout
iHyde wrote:I should mention I live out on the Olympic Peninsula and we get about 3 meters of rain between Oct. and May
3m!!
that is a bit of rainfall, think you will struggle with flexible laying with these type of setts.especially with that amount of rain
lay like the cookie man does
LLL
Posted: Tue Aug 16, 2011 8:22 pm
by Pablo
3m thats on a good year Tony sometimes they can get that in a few weeks I've never seen rain like it in my life it's incredible. Up in the mountains it all falls as snow meaning it can be 100ft deep at the end of winter With regards laying the setts if you lay your edge course perfectly then you can use it as a guide to roughly lay each course and beat them level with a deadblow hammer and some straight 2x4 laid edge to edge it'll be much quicker and more accurate. It's best if the mix is a bit wet and I wouldn't top the joints up they'll naturally find their own level as you tap the setts into the mix. If you pointed them with KDS it'll be a haven for weeds moss and algae because it's so wet over the winter. The way I see it you have 3 options,
1. Use KDS but apply a liberal amount of joint stabiliser to seal the sand and help prevent the growth. Also the setts could do with a few coats of sealant due to their light colour which if left untreated will quickly turn green.
2. Lay them with a 8-10mm joint and slurry point them with a 3:1 grit sand and cement mix. As you clean it the grit will become exposed and make the pointing less formal.
3. Lay them with a 8-10mm joint and point them with a ready mixed resin pointing compound. These products are very porous and so is the base so water won't collect. Here's an example of what I'm talking about it's also much less formal looking than trowelled mortar.
Allowing the plants to spill onto the path will be the best way of softening the look of the paving.
Posted: Tue Aug 16, 2011 8:44 pm
by lutonlagerlout
I am worried about the long term of resin mortars
I will be sending 2 photos of romex terrasse to romex shortly to see why it looks crap after 4 years
LLL
Posted: Tue Aug 16, 2011 8:47 pm
by ken
why? whats up with it?
Posted: Tue Aug 16, 2011 8:57 pm
by Pablo
I haven't had any experience of the problems you've encountered Tony could it be anything to do with cleaning methods or chemicals. Or do you reckon it's frost related. That won't be a problem in Seattle they're much milder than us.
Posted: Wed Aug 17, 2011 5:23 pm
by iHyde
Thanks for the tip on using the board to level. Will give that a go. Got a good start yesterday using the 6:1 slightly moist on top of wetted sub-base but, surprise, slow going ) Fair number of cuts due to radius on the curved walkway and radius on the course curve. Fun puzzle, lots of learning mistakes corrected.
I've set the joints fairly tight, 6mm at the most. You're right, enough base comes up with the compaction of the sets to nicely hold them apart and lock them in place. Partially filled a few emptier joints as I went and misted them a bit. Very happy with the look and really glad I got the advice here to go the bound base route.
Still looking to a top off with a sand pointing, there is a screened black sharp crusher fines I can get from a local quarry, although not kiln dried. Since the joints will only have 12mm of sand depth at most on top of hardened 6:1 base material, I can't see weeds being too big a problem with that little depth of grow medium ... and I'm prepared to be wrong. I liked your example with the large flags but still too finished looking for me.
By the way, I'm near the mountains so winter temps do get down to -10c and sometimes briefly to - 18c
Posted: Tue Aug 30, 2011 7:04 am
by Pablo
Looks great well done. You may have to open up the smaller joints with a small grinder though to make them accept mortar and be slightly more uniform. Because you've topped the joints up a resin mortar won't work it needs a joint of min 1 inch. In fact the joints are a little to shallow for any mortar if you can't get it to bond with the base then the frost will kill it. It's possible a high strength exterior tile grout may be the best option for you or bite the bullet and relay them without topping up.
Posted: Tue Aug 30, 2011 4:38 pm
by lutonlagerlout
I like it
its sooo different to what i normally see
thinking out side the box as it were
pablo is right of course
the jointing need to be done in 1 go
topping up is sure to fail mate
LLL
)
