Posted: Thu Jan 05, 2012 5:01 pm
Hi there,
You have a great website. For a complete novice I now feel I’m becoming quite the expert! I have a bit of a question that I can’t seem to find the answer to on there though.
My project is a tiny patio for a static caravan, approx. 2.5m x 2.0m. I have natural green slate from a random pack and have drawn up on the design and almost ‘sussed’ how I’m going to do it. Unfortunately the patio is to be slightly raised (Approx. 200mm), so I have had to improvise a bit. My procedure so far is as follows:
• Demolish old patio and excavate to approximately 50mm.
• Construct plywood to be used as shoring for the elevation.
• Excavate a small trench (approx. 100mm deep by 300mm wide) around the permiter, against the shoring.
• Pour concrete into the new trench and push up to the shoring, approximately 300mm deep (Giving a 150mm rise) and the full width of the trench. I will use a triangular gradient so that the concrete gets shallower the closer to the edge of the trench and the middle of the patio it gets.
• Allow to cure.
• Fill the middle with 150mm of 50mm crusher run. Allow a slight gradient away from the caravan for drainage.
• Compact using my dad’s whacker plate, multiple passes.
• I now have 50mm left before reaching the top.
• This 50mm is to be filled with bedding material, then the flags painted with an SBR/cement mix before laying onto the bedding and tapping down until level.
• The bare concrete sides are to be cladded using more slate and bedding material/adhesive.
• Jointing/pointing is going to be done with the wet method for VDW840+ as recommended by you.
I’m pretty happy with all of this, except for the following:
• Should I use a weed membrane? Where should I put it? I have some heavy duty stuff that lets water through (I know this’s important) and the site is known for brambles growing through the gaps in the flags beneath the caravans.
• Will my concrete edging be strong enough to keep all the crusher run in the middle?
• Here’s the tricky part. The patio has to take the weight of a set of three brick steps up to the caravan with matching slate for the step surface. I have read on parts of the site that excess weight could cause ‘pumping’ with the crusher run. I don’t fancy having my beautiful patio ruined a week after completion by a set of heavy steps being built on top! The steps are to go very close to the right edge of the patio so I can imagine either the right hand concrete shoring to crack or the middle/left of the patio to rise as the weight is put on the right.
After a long time of planning, I think I’m nearly there. Thanks for putting such a great resource on the internet!
You have a great website. For a complete novice I now feel I’m becoming quite the expert! I have a bit of a question that I can’t seem to find the answer to on there though.
My project is a tiny patio for a static caravan, approx. 2.5m x 2.0m. I have natural green slate from a random pack and have drawn up on the design and almost ‘sussed’ how I’m going to do it. Unfortunately the patio is to be slightly raised (Approx. 200mm), so I have had to improvise a bit. My procedure so far is as follows:
• Demolish old patio and excavate to approximately 50mm.
• Construct plywood to be used as shoring for the elevation.
• Excavate a small trench (approx. 100mm deep by 300mm wide) around the permiter, against the shoring.
• Pour concrete into the new trench and push up to the shoring, approximately 300mm deep (Giving a 150mm rise) and the full width of the trench. I will use a triangular gradient so that the concrete gets shallower the closer to the edge of the trench and the middle of the patio it gets.
• Allow to cure.
• Fill the middle with 150mm of 50mm crusher run. Allow a slight gradient away from the caravan for drainage.
• Compact using my dad’s whacker plate, multiple passes.
• I now have 50mm left before reaching the top.
• This 50mm is to be filled with bedding material, then the flags painted with an SBR/cement mix before laying onto the bedding and tapping down until level.
• The bare concrete sides are to be cladded using more slate and bedding material/adhesive.
• Jointing/pointing is going to be done with the wet method for VDW840+ as recommended by you.
I’m pretty happy with all of this, except for the following:
• Should I use a weed membrane? Where should I put it? I have some heavy duty stuff that lets water through (I know this’s important) and the site is known for brambles growing through the gaps in the flags beneath the caravans.
• Will my concrete edging be strong enough to keep all the crusher run in the middle?
• Here’s the tricky part. The patio has to take the weight of a set of three brick steps up to the caravan with matching slate for the step surface. I have read on parts of the site that excess weight could cause ‘pumping’ with the crusher run. I don’t fancy having my beautiful patio ruined a week after completion by a set of heavy steps being built on top! The steps are to go very close to the right edge of the patio so I can imagine either the right hand concrete shoring to crack or the middle/left of the patio to rise as the weight is put on the right.
After a long time of planning, I think I’m nearly there. Thanks for putting such a great resource on the internet!