Laying a new Concrete driveway

[kvfilms]

Hi,

I'm in the very early stages of planning to dig up my old concrete drive, as it's cracked and uneven, and after 30 odd years has dropped in places too, so it's time for a face lift.

I've got as far as finding out that it needs to be at least 100mm deep, but at a good 10 metres long, if not more, it could do with its own drainage, amongst other things....


The drive runs parallel with the house and because of this the properties sewer and rain water drains are on the drive. Are these going to pose a problem in digging up the old concrete and laying new concrete, or is it as simple as working around them and not digging too deep? or do I need to notify the water authority etc of my plans?

Also, am I allowed to fit a new rain water drainage system onto the drive and connect it to the existing house rain water system or does the water authority need to approve that? Secondly, I've heard there's new rules about driveway drainage like those ducts you often see with block paved drives etc, is it compulsory to install some degree of drainage system on a private property, if so where do you connect it to?

And last but not least obviously being a driveway and a long one at that, it will need to be sloped (as the existing one is) from street level upwards, not forgetting the drains and manhole covers are on the drive, what is the rough percentage the slop should be? 10% ish?


Cheers,

KVFilms

 

[toptec]

I recently replaced my gravelled driveway with block paving. This too included a number of man hole covers for drains and other services. I did not have to notify any of the companies. I dug out the footings for the scalpings and made sure that the top of the covers matched my top level of pavers. You can buy good quality covers nowadays.

Regarding the water run offs - I would give your local planning office a call, their advice is free. They will tell you what, if anything, has changed regarding building regulations especially matters affecting the drains. I don't recall any compulsary requirements for surface water - just common sense.

As far as your slope is concerned water will run off a 1% slope. The slope is usually governed by the levels of your DPC in your house.

One other point if you are doing a 10 metre stretch of concrete, it will have to be done in sections to avoid stress cracks.

Have fun

 

[kvfilms]

Thanks for your reply I was beginning to think no one was going to reply... most helpful.. cheers! How big should the sections be then? thus avoiding stress craacks etc, but at the same time not having loads of individual sections of concrete, not least as a rough estimate, it could be more than 10 metres.... not had chance to measure properly yet

just out of interest, what sort of time scale would I be looking at for each section... i.e laying one section and moving onto the next section?... i.e drying time etc


Cheers

 

[marshman]

100mm deep + 150mm compacted hardcore minimum normally 200mm hardcore,
if you lay the concrete 150mm thick and the ground is tight - firm, this will reduce the hardcore to 50 / 70mm
just for leveling, still needs compacting with a wacker plate, (local hire shop) also saves on digging out.
hardcore type, 150/200mm----- 2 inch down (carstone / limestone. 50/70mm ask for fines,
if hardcore is all ready under the old concrete you'll just need to recompact, (all best done when damp).
yes you can connect new rain water drains to existing rain system not rain to sewer thou.
depending on the age of the house rain and sewer maybe all one system.
(is it compulsory) as far as I know only on new build. (if so where do you connect it to) existing rain system .
falls / (slope) across - along or both direction aim for 10mm a meter no less than 5mm.
first thing lift your drain lids and look at 1. the depth to bottom of pipe this will give you an idea of height and type
of new drain grate and distance, rain water pipe can layed as fleet as 1mm a meter or level at a push.
expect an outlet depth (bottom of pipe) 300mm minimum from finish height (top of grate) vary on type chosen.
2. type of existing pipe, clay or salt glaze, disk cutter required to cut pipe line, new 110mm plastic, old hand saw.
3. type of chamber, brick or plastic, if brick and its deep enough you may can punch a hole through the side
for your new drain pipe if plastic 115mm core bit, can also be used through the brick but you'll need the right drill, (hire shop)
4. lid and its frame, you'll most likely shake any frame lose from a brick chamber, clean the old mortar off with taps from a
hammer (hitting mortar) don't hit a cast iron frame, rebed them with 3&1 or 4&1 mortar mix setting them to your new falls,
it can help a lot to reset all the lids to your new drive heights than making the drive work to the lids,
i.e.. add or remove brick courses, mortar bed thickness.
concrete heights if you are going to lay it against the house wall 150mm or 2 bricks below damp course with cross fall away
from house if you are leaving a gap 100mm minimum for gravel you can come up a brick still having a cross fall away.
expansion joints, really depends on how you are laying it, mixing it yourself ( when you're bu****ed),
lets say your drive is 3m x 10m two expansion joints at 3.3m will do depending where the drains are if you concrete against
the wall then you should add one more. (personally I wouldn't concrete to any wall and certainly not without expanding foam
strip between them), finish section using 9 or 10mm x 100m tongue grove board as shutter (tongue up) and leave in place
when you start the next section it don't matter if your concrete is 150mm thick this is enough for a controlled break or
expansion joint ( gets the weeds growing in a straight line for an easy kill).
ready mixed lorry load, concrete all in one load / day and add the boards as you go ( cut to length and laying at the sides ready,
friends who you've talk into helping and wearing wellies for this mad rush will require cold beers to replace sweat loss).
also another is open this way for expansion joints that is next day or two you can hire a concrete floor saw and put cuts
across the concrete a 100mm deep,( down side to this is mess and noise).

 

[noseall]

i recently got a rebate from the water company, after proving that i collected and drained ALL the rainwater upon my property.

you will be charged though, even if your drive slopes towards the footpath and that surface water falls beyond your boundary.