Laying granite setts on rooftop garden - Laying granite setts on rooftop garden

[smk3142]

Hi Everybody!

We are in the process of tendering for a project where we have to lay 100 x 100 x 50mm granite setts on a rooftop garden.

The maximum build-up we can achieve is 60mm (leaving only 10mm for a bed). Since the paving is on a flat roof, there will be a certain amount of flexibility required (although from our site visit, the deflection on the roof structure is undetectable). Nevertheless, there will be a certain level of deflection and so we will have to install the granite setts on a flexible compound.

We have wondered if using a lime mortar mix would be sufficient for the bed because of its flexible / forgiving properties. However, we are just concerned that the setts may start to delaminate from the mortar bed.

We are also considering using a good quality external grade / flexible tile adhesive and perhaps use a jointing compound for the pointing such as Everbuild's Geo-Fix Paving Jointing Compound because of it's flexible properties.

As I mentioned earlier, there is no detectable deflection in the roof structure, but there is bound to be some level of movement. The roof structure consists of heavy section steel universal beams, with a 38mm HDX P5 moisture resistant tongue and groove board and a fibreglass finish.

We were just wondering if anybody had experience of working with such restrictions and could offer any advise on a method / specification for a flexible 10mm bed and joints.

Many Thanks

[Al Jardin]

Hi Smk
Must not use the word Geofix. Swearing not allowed. You'll upset people.
How about thinner slabs and, as you said, flexible tile adhesive. Or talk to architect/structural engineer.

Al

[cookiewales]

Steintec have a system tuf bond flexible beding and jointing speak to Jonny he will sort you out

[seanandruby]

You have had a structural engineer in to access if it will take the extra load, haven't you ???

[lutonlagerlout]

^^ all of the above
we dont mention geo-shite on this forum,its the devils work

how about marshalls cobbletech it sits on sand so is flexible
personally I dont like to see stone or concrete products sitting on timber
it goes against everything I have ever learned
LLL

[smk3142]

Thanks Al Jardin, cookiewales, seanandruby and lutonlagerlout. The roof structure has been designed to take 2.2 metric tonnes per square meter, so loading is not an issue (thankfully).

cookiewales:

I will have a look at the tuf bond flexible bedding so thanks for this.

lutonlagerlout:

I will also have a look at Marshalls Cobbletech so thanks for this suggestion. Unfortunately, the decision on specification does not rest with me. Granite is the preferred choice for it's aesthetic appeal (it's a rather upmarket project). I will let you know how we get on.

Thanks to you all once again for commenting.

[cookiewales]

I laid granite paving above Waterloo railway station many years ago at that loading you could use reclaimed setts give me a shout if your looking for some cheers cookie

[smk3142]

Thanks Cookiewales. We'd love to use reclaimed but we're restricted to an overall build-up of 60mm.

[r896neo]

Tobermore used to do granite setts 100mmx100mm on a mat similar to the cobbletech system but they were only 25mm thick.

I'm not sure if they still do it and you may be out of their range but worth a look.

[cookiewales]

Thanks Cookiewales. We'd love to use reclaimed but we're restricted to an overall build-up of 60mm.

you can slice them have done it myself with bench saw what m2 is your project i even sliced the big sandstone setts for my show garden in tat-ton park show :p its on my website

[smk3142]

Cookiewales, got in touch with SteinTec on your recommendation and they have been brilliant. We've sorted out a specification that we are more than happy with.

Thanks for your help!!!:D

[cookiewales]

Cookiewales, got in touch with SteinTec on your recommendation and they have been brilliant. We've sorted out a specification that we are more than happy with.

Thanks for your help!!!:D

glad you got sorted what system are you using ps need any setts laying give me a shout