Overlay bitmac??? - Can asphalt be used as a base?
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moot de noo
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- Location: west yorks
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Tony McC
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Yes ....but.
You need to provide some way of draining the bedding layer: typical asphalt/bitmac surfaces are insufficiently permeable to allow the bedding material to be freely drained. This can lead to the material becoming saturated and fluidised, which, in turn, allows it to be squeezed and pumped and before you know it, the block paving is channelised or loose or all over the place.
There's a few suggested strategies on the Paving over a Base page.
You need to provide some way of draining the bedding layer: typical asphalt/bitmac surfaces are insufficiently permeable to allow the bedding material to be freely drained. This can lead to the material becoming saturated and fluidised, which, in turn, allows it to be squeezed and pumped and before you know it, the block paving is channelised or loose or all over the place.
There's a few suggested strategies on the Paving over a Base page.
Site Agent - Pavingexpert
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moot de noo
- Posts: 11
- Joined: Fri Jun 03, 2005 7:38 pm
- Location: west yorks
Hi Tony,
That's one of the reason's I asked - the bit about paving over a base covers concrete but indicates that asphalt should be removed to subbase level.
My thought is that provided your bedding sand is sufficiently sharp the water can get out sideways?
Just a thought really - my real problem is that this is my drive and there's already 50mm of 6mm dense on it and I've 120 sq metres (about 15 tonne by my reckoning)
Any body know any cheap skip hire co's???? :;):
That's one of the reason's I asked - the bit about paving over a base covers concrete but indicates that asphalt should be removed to subbase level.
My thought is that provided your bedding sand is sufficiently sharp the water can get out sideways?
Just a thought really - my real problem is that this is my drive and there's already 50mm of 6mm dense on it and I've 120 sq metres (about 15 tonne by my reckoning)
Any body know any cheap skip hire co's???? :;):
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Tony McC
- Site Admin
- Posts: 8346
- Joined: Mon Jul 05, 2004 7:27 pm
- Location: Warrington, People's Republic of South Lancashire
- Contact:
Water could get out "sideways" if there'sno bound material at the sides. However, with properly constructed block paving, there should be some bound material at the edges - either concrete bedded edge courses, a wall, or something 'fixed'.
I think I might need to clarify the info given on that page - for residential driveways, it's often easier to rip up the bitmac and expose the sub-base, but it's not always necessary. Further, many low-speed, block paved residential cul-de-sacs are actually constructed over a bitmac base.
Could you not just cut core holes into the bitmac at, say, 1800mm centres, cover the lot with Terram or TDP115, and then pave over that as per normal?
I think I might need to clarify the info given on that page - for residential driveways, it's often easier to rip up the bitmac and expose the sub-base, but it's not always necessary. Further, many low-speed, block paved residential cul-de-sacs are actually constructed over a bitmac base.
Could you not just cut core holes into the bitmac at, say, 1800mm centres, cover the lot with Terram or TDP115, and then pave over that as per normal?
Site Agent - Pavingexpert
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moot de noo
- Posts: 11
- Joined: Fri Jun 03, 2005 7:38 pm
- Location: west yorks
