Phil

iTrader: (1)

I'm extending my garage at the moment and have taken out the old concrete base (about a foot of reinforced concrete ) to dig a pit. I would like the new pit to be solid concrete, to prevent any water ingress etc. Has anyone done this?

I was thinking the rough process would be something like:

Line with DPM
Put the steel reinforcement in the floor and sides
Pour some concrete for the floor
Insert prebuilt shuttering to maintain shape (including sump and recessed sides to rest pit cover)
Pour surrounding concrete to fill in the sides
Remove shuttering when dry

Any builders or people who have done similar with more of a clue than me?

B16JUS

i think you can buy pre built pits with steps and everything you dig the hole put them in then fill in the sides.

Ratty

iTrader: (1)

Like this

http://mech-mate.co.uk/How-to-Fit-a-Pit.html

macrs

I would personally say thats the way forward!

I know its a long time ago...but when my dad built his garage some forty odd years ago, he sank a pit into it.

It was fully lined and sealed to the best level materials would allow back in the 60's. Its fully concrete lined and during the winter it always fills up with water, not seriously but enough to be an annoyance....

If I was building one today i'd use one of those pre cast pits in a second.. Nice and dry with all the neat little extras too!

Hope this helps!

Danster76

iTrader: (2)

I have a concrete pit in my garage and it always has 1-3cm of water in the bottom. When I get it sucked out it takes about 3-4weeks before it gets annoying again.

These pits look really good but at a cost I should think. If you can afford it I think these would be the tool.

Happy digging!

Phil

iTrader: (1)

They look good, possibly slightly on the thin side at the bottom of the pit. They are sending me over a full price list but it seems prices start at just shy of Ł1k for the smallest size. You still have to pour concrete and rebar the sides for these pits also, so it seems like it would be quite a bit more expensive than a DIY attempt.

Ratty

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In todays market its worth asking for discount

Phil

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They offer a 5% discount to anyone in a car club which is a start. Still probably going with the original plan though, so any builders? Was hoping to avoid leaks by pouring the whole lot in one go so there were no joins for water to come in through.

Ratty

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Use a pond liner to line the walls first

ESCYSCOTT

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dig it wide enough to lay a good base foundation with a large damp proof membrane then "build" the sidesetc with concrete blocks then fill in the sides with concrete afterwards. Thats the way I would do it but it may be wrong.

righthooker

as Scott says but try to liner the bottom and behind the concrete blocks in one pice of membrane , creating a tank, membrane is 4m wide and as long enogh so it should do the trick.
I wold go for a 150mm block too for stability.Beats suttering all day long

ESCYSCOTT

iTrader: (1)

..........and easier to paint white afterwards!!! LOL

michael harbour

why don,t you get a steal one made and sink it in?

Graceland

We did our pit by breaking through the concrete floor base and then digging down 5 foot and then a lot wider and longer than needed.

After that mamoth job and some 10 ton of mud, clay and rubble later, we put a large tarpauline in the hole and used that as the damp proofing. Filled the base with concrete and then allowed it to set. Then we built up the walls using breezeblocks and then once set backfilled using some of the clay and rubble we removed. We also used the hosepipe to settle the backfill while putting more in and then skimmed concrete on the top 6" to level the floor while using some angle iron for the top lips.

All has been perfect and no water ingress at all

Phil

iTrader: (1)

Sounds like concrete blocks backfilled with concrete may be easier then!

Graceland

Backfill with the crap you dig out and then the last 4-6" use concrete

Graceland

You may also need one of these to do the work for you

G420 DEL

pc09 worst! lol not really bad depending what your usein it for, tracked plenty of them through houses to back gardens.

Phil

iTrader: (1)

Yes don't worry, mini digger is already planned - for 90 a day i'd be stupid not to!