Advice for my front patio - Indian sandstone patio and sub base prep

[Adamchandler93]

Hello!
I have worked in the construction industry for the last 5 years (only 23) and have recently bought my own home.although I am experienced in bricklaying and groundwork I have not undertaken many projects of my own. I was hoping for some advice on my patio I am to flag as the existing is all crazy paving, which is knackered, buckled, falling all sorts of directions and unsightly. The existing is luckily 150 down from the threshold and I have drainage points which building control have told me is fine to run into. The existing has been bedded directly onto the sub grade which is a very soft and wet clay. With the nature of the sub grade is 100mm of hardcore essential to stop ground movement? Also because the ground is not very absorbant does this mean any decorative gravel areas and small soakaway for boiler will just bog up? Also there are two airbricks which sit almost level with the patio now. How can I stop water from running into them? ( and slugs! We had about 15 come in through the airbricks one time!!) Thanks a lot any advice is much appreciated.

[Tony McC]

Definitely use a sub-base of Type 1 material rather than the any-owld-shite "hardcore". That will help overcome the soft, boggy nature of the clay.

For the deco gravel areas, how big are these? If they are under 5m² you will probably be OK, but boost the effectiveness by putting a sub-base beneath that, too.

With the air bricks, stay 15-20mm lower than any opening and make sure paving is falling *away* from the masonry.

As for the slugs - if you can solve that one, you'd make millions from gardeners! There are all sorts of poisons, pellets and potions, but when the slimy gits are coming in through an air-brick, one of the simplest, most effective, long-lasting and cheapest solutions is to place a strip of copper wire around the vents. Slugs will not cross copper - it short-circuits their internal electro-chemistry. This is a trick many gardeners use with pots: a band of copper wire around the pot will prevent any slugs (or snails) slithering up the side to wreak havoc on your precious blooms.

[seanandruby]

As regards air bricks i usually do a small edging kerb arrangement, the length of the air brick and 50 to 100ml out filled with shingle/ pea gravel. Not ideal but keeps them dry.

[Adamchandler93]

Thanks for the advice never knew that about the copper wire!!! About 2 square metres of gravel altogether if we go for that. I was told the overflow pipe for the boiler, (which at the moment falls right near the airbrick and puddles across the flags) needs to run into a small 300x300 soakaway. Im sure I could use that with the edging around the airbrick but is the soakaway OK next to the house wall? I know they say as far away from footings as possible but it would only be a small amount of water.

[Tony McC]

Boiler overflow is minimal so next to the house should be OK

[Edgar]

Something is wrong with the boiler or header tank. Faulty ball valve washer? It will be diluting the inhibitor. Needs fixing. There shouldn't be any overflow.
Edgar

[rab1]

Condensing boiler has a constant run off, the water is acid and can/will damage cement based products over time

[Edgar]

OK. But not "Boiler overflow". Condensate is a different thing - and I agree it is acidic. Some boilers don't continually release the condensate but hold it back and let go from time to time. That way reduces the chance of freezing in the condensate pipe.
Terminology!
Edgar

[lutonlagerlout]

limestone chippings are good for condensate !
it dissolves them over time
LLL

[rxbren]

Condensate pipe should go into lime if the pipe is external you'll want to insulate it as there was a run of condensate freezing from outside and working its way upto the boiler and knackering boilers. Many plumbers now just plumb it into kitchen waste

[Adamchandler93]

Pretty sure it is a condensing boiler. It's not a little pipe that sticks out its like 40mm pipe running down and plumber told me it needs to run into a little soakaway area. So I'm sure chippings will be fine! Cheers for the help lads I'll be coming to the brew cabin more in the future