Posted: Wed May 05, 2010 9:40 am
Hello everyone
I joined last night and am pleased to find such a great website.
Please can anyone offer any advice on remedial work for a patio that was done from scratch less than 12 months ago? Unfortunately I employed a generalist builder to do my Mum’s garden. Luckily I’ve found this website!! I need to employ a landscape garden/patio expert to remedial work, but this time I want to know what should be done exactly so that the techniques, materials and quantities used are correct and to a high standard. This time I would like the job to be detailed in a contract before the work starts to avoid further problems.
Description of patio:
- Patio size circa 38 sqm with Bradstone utility paving slabs 450 x 450. Its about 30foot long and 12 foot wide. A terraced house.
- split on 2 levels as the garden is on a slope, with a retaining wall and a step to lower level. The retaining wall and step has London Bricks facing out with a patio slab on top.
- The patio has
-black plastic Damp Proof plastic under the whole surface of the patio (he told me he was putting down a membrane to stop weeds growing up through patio)
- then ballast
- then sharp sand
- the slabs and some type of dry sand without any cement, in between the slabs.
- He built a step one London brick high - on top of the patio meeting the French doors of the house, the full width of the French doors. The step was butted to the house bricks and filled with ballast. When the new French doors were fitted the window fitter pointed out that the step was acting like a sponge and had soaked the house bricks. The pointing of the house bricks had crumbled away so the bricks were loose and a couple had cracked, a little damp inside the house on the skirting board. There had never been any problems with damp externally or internally ever before. We took the step away from the house.
- Unfortunately the patio finishes less 150mm from the DPC
- At the bottom of the garden, the patio finishes circa 100mm from a very old wall and is filled with slate chippings – this is supposed to be a ‘French’ drain
Despite the hot summer last year the slabs didn’t dry out – they there wet around the edges with a round dry patch in middle. But now this year they do finally seem to have dried out across the surface of each slab now its sunnier and the green on the slabs is going where its in the sun. I’m not sure why! The ‘sand’ type material in between the slabs has all gone green and looks like it could all turn into moss. The slabs have totally discoloured.
-The soil in the garden has some clay content.
The only good point is – all patio slabs are all level i.e. wherever you place a chair, the chair doesn’t rock at all.
Can any one please offer suggestions as to the correct remedial works?
What do people think of the following suggested remedial works?:
-cut patio back from the house bricks (as too close to house DPC) Horizontally - 150mm gap between house bricks and patio slabs? Vertically – 300mm from house DPC and then filled with slate chippings so that chippings finish 150 mm below house DPC? Should there be a retaining wall directly under the edge of the patio to keep the earth next the house in an upright position to stop crumbling into the ‘trench’?
-cut patio back from the wall at the bottom of the garden (to improve drainage) Should be 600mm from the wall? What should be dug/ done in the drain area?
-cut back patio from the 2 parallel sides running the length of the garden (so that if fence posts need to be replaced, the patio would be undisturbed) What distance?
- replace the current sand type mixture between the patio slabs with wet mortar pointing 1:3 cement sand (to make waterproof, to stop water penetrating vertically through the patio as it currently does)
- repair/replace/rectify the drain next to the house which handles has the roof gutter rainwater for this house and the 2 either side. Previously the gutter pipe finished inside the drain so there wasn’t the chance of any splashing up against the house as it does currently. Not sure best way to do this.
- perhaps - replace the retaining wall and the step leading down to the lower level. Maybe this does or doesn't need to be replaced? I don’t think he used any vertical damp proof. He put some weep holes using some plastic pipe I had left over from when my Mum had some plumbing work done, not the 3 /4 tubing pipe. I’m worried that the wall might blow and crack after some cold weather. Also, its green and looks like moss will be covering it soon. I’m guessing he filled the step with ballast material the same way he did for the house step he built, and so created a ‘sponge’ next to the retaining wall.
-At the bottom of the garden, the patio is too close to the 80yr old wall at the bottom of the garden ie the patio is 30mm from this wall. To increase the drainage, what distance should the patio be from this wall? 600mm? What prep work should be done to this space? and should it finish be lower than the patio? Just slate chippings ok?
What distance should the patio be from the fences that run the full length parallel to the patio? What is recommended so that the patio would not need to be disturbed if the fence posts need to be replaced? 150mm?
I would like to replace the current sand pointing with mortar pointing –
is 1 cement: 3 sand okay? Should the pointing be smooth or with a ridge?
Should the patio be damped with water before pointing to avoid the slabs sucking up the moisture form the mortar and weakening the mortar and avoid the picture frame effect? Because of the 'PDC plastic' under the patio, I was thinking maybe better to do pointing when its dry to avoid trapping excess water between the patio and the plastic?
I’m sorry for the very long email. I’d be very grateful for any help!
Thank you in advance
Helsbels
I joined last night and am pleased to find such a great website.
Please can anyone offer any advice on remedial work for a patio that was done from scratch less than 12 months ago? Unfortunately I employed a generalist builder to do my Mum’s garden. Luckily I’ve found this website!! I need to employ a landscape garden/patio expert to remedial work, but this time I want to know what should be done exactly so that the techniques, materials and quantities used are correct and to a high standard. This time I would like the job to be detailed in a contract before the work starts to avoid further problems.
Description of patio:
- Patio size circa 38 sqm with Bradstone utility paving slabs 450 x 450. Its about 30foot long and 12 foot wide. A terraced house.
- split on 2 levels as the garden is on a slope, with a retaining wall and a step to lower level. The retaining wall and step has London Bricks facing out with a patio slab on top.
- The patio has
-black plastic Damp Proof plastic under the whole surface of the patio (he told me he was putting down a membrane to stop weeds growing up through patio)
- then ballast
- then sharp sand
- the slabs and some type of dry sand without any cement, in between the slabs.
- He built a step one London brick high - on top of the patio meeting the French doors of the house, the full width of the French doors. The step was butted to the house bricks and filled with ballast. When the new French doors were fitted the window fitter pointed out that the step was acting like a sponge and had soaked the house bricks. The pointing of the house bricks had crumbled away so the bricks were loose and a couple had cracked, a little damp inside the house on the skirting board. There had never been any problems with damp externally or internally ever before. We took the step away from the house.
- Unfortunately the patio finishes less 150mm from the DPC
- At the bottom of the garden, the patio finishes circa 100mm from a very old wall and is filled with slate chippings – this is supposed to be a ‘French’ drain
Despite the hot summer last year the slabs didn’t dry out – they there wet around the edges with a round dry patch in middle. But now this year they do finally seem to have dried out across the surface of each slab now its sunnier and the green on the slabs is going where its in the sun. I’m not sure why! The ‘sand’ type material in between the slabs has all gone green and looks like it could all turn into moss. The slabs have totally discoloured.
-The soil in the garden has some clay content.
The only good point is – all patio slabs are all level i.e. wherever you place a chair, the chair doesn’t rock at all.
Can any one please offer suggestions as to the correct remedial works?
What do people think of the following suggested remedial works?:
-cut patio back from the house bricks (as too close to house DPC) Horizontally - 150mm gap between house bricks and patio slabs? Vertically – 300mm from house DPC and then filled with slate chippings so that chippings finish 150 mm below house DPC? Should there be a retaining wall directly under the edge of the patio to keep the earth next the house in an upright position to stop crumbling into the ‘trench’?
-cut patio back from the wall at the bottom of the garden (to improve drainage) Should be 600mm from the wall? What should be dug/ done in the drain area?
-cut back patio from the 2 parallel sides running the length of the garden (so that if fence posts need to be replaced, the patio would be undisturbed) What distance?
- replace the current sand type mixture between the patio slabs with wet mortar pointing 1:3 cement sand (to make waterproof, to stop water penetrating vertically through the patio as it currently does)
- repair/replace/rectify the drain next to the house which handles has the roof gutter rainwater for this house and the 2 either side. Previously the gutter pipe finished inside the drain so there wasn’t the chance of any splashing up against the house as it does currently. Not sure best way to do this.
- perhaps - replace the retaining wall and the step leading down to the lower level. Maybe this does or doesn't need to be replaced? I don’t think he used any vertical damp proof. He put some weep holes using some plastic pipe I had left over from when my Mum had some plumbing work done, not the 3 /4 tubing pipe. I’m worried that the wall might blow and crack after some cold weather. Also, its green and looks like moss will be covering it soon. I’m guessing he filled the step with ballast material the same way he did for the house step he built, and so created a ‘sponge’ next to the retaining wall.
-At the bottom of the garden, the patio is too close to the 80yr old wall at the bottom of the garden ie the patio is 30mm from this wall. To increase the drainage, what distance should the patio be from this wall? 600mm? What prep work should be done to this space? and should it finish be lower than the patio? Just slate chippings ok?
What distance should the patio be from the fences that run the full length parallel to the patio? What is recommended so that the patio would not need to be disturbed if the fence posts need to be replaced? 150mm?
I would like to replace the current sand pointing with mortar pointing –
is 1 cement: 3 sand okay? Should the pointing be smooth or with a ridge?
Should the patio be damped with water before pointing to avoid the slabs sucking up the moisture form the mortar and weakening the mortar and avoid the picture frame effect? Because of the 'PDC plastic' under the patio, I was thinking maybe better to do pointing when its dry to avoid trapping excess water between the patio and the plastic?
I’m sorry for the very long email. I’d be very grateful for any help!
Thank you in advance
Helsbels
