hi. trying to fix a wet spot by the driveway. saw these concrete boxes with little circles you knock out for the pipe on all 4 sides. want something stout enough a truck wont crush.
is 4 inch pipe the normal size. and do they make the boxes so 3 inch fits the same one or do i need two diferent boxes
thanks
grovewalker
Do you have a photo of the problem?
A photo and some info on the drive - is it tarmac or gravel or paved? The wet spot - is it because of a depression in the drive that prevents normal surface run off? The plan for a soak away - where to? Why so much pipework - would a drainage ditch filled with stone & gravel (then covered) no be sufficient?
The concrete ‘box’ you describe is most often used to connect multiple run-offs - such as a couple from guttering down pipes and then a pipe to lead to a soak away. It also is used to provide access / sight of the water run-off in case something gets blocked. A place you can lift the lid and then rod or power wash up/down the pipe work But you only seem to have one wet area and one run-off requirement - so why the need for a box?
Note - you can easily get metal lids for these concrete boxes although you probably need a cast iron one if driving heavy vehicles over it. See back to my suggestion of a simple ditch to avoid all this cost and complexity.
Sorry, lots of questions needed to work out the best asnwer.
spitfire i dont really have a picture, its just wet by the garage. lincolnshire if your asking what the drive is its asphalt i think thats what you mean by tarmac?? the water sits in a low spot there. not sure about a soakaway or ditch thing, i just figured id put one of those concrete boxes with the holes you knock out. maybe thats not even the right thing
Hi Grovewalker, and welcome to the forum. Can’t you just raise the low spot with a shovel full of asphfalt (Tarmac)
so the water just runs off to the side.
Either that, or you will have to deface the drive trying to solve the problem.
Has the drive sunk in that spot, possibly with heavy transport driving over it?
OldGreyFox i dont really get what you mean about raising it with asphalt. theres pots and planters sitting there by the garage so i cant just pile blacktop on it. thats why i figured i needed one of those concrete boxes with the knock out holes, to catch the water under there somehow. wait are you saying the trucks made a dip?? i thought it was always kinda low. still dont know what size box takes both 3 inch and 4 inch pipe tho
Let’s see if we understand your problem.
There is a dip in the asphalt drive and it is quite a large area that is dipped & collecting water.
The answer would either be to add material (asphalt) to change the dip to a very slight mound or to dig drainage.
The size and location (plus other obstacles) would make the idea of adding more asphalt, to create a slight mound, impractical or a lot of work / material.
Therefore digging drainage could be the better answer. For this, you are considering digging out a small section of asphalt, placing a drain of some sort in the ground, adding a pipe to allow the flow of water away, and covering with a strong lid that allows water to drip into the drain. The drain here might be the concrete box you have mentioned.
Is that where we are?
your problem is Tarmac. The question I ask is how big it the drive and would it be worth replacing with blockwork paving. that is what i have and it is huge area , any surface water soon goes Not knowing what the local area is like it might stand out too much or too costly.
With so little detail to go on in your post one can only make wild guesses to the solution.
I would not trust those concrete boxes you mention too easy to get damaged. Ripping up old tarmac may result in a lot more tarmac coming up that you want. So you would have to cut out a work area first
thinking on it a little more a small round /square decorative brick block area where the water lies would work. Lay the brick blocks on a decent depth of sand and problem gone. not building bricks but paving brick as below
https://www.ebay.co.uk/itm/398160796962?_u
No worry abock trucks or lorries going on them
put in a french drain rather than wasting your time looking for the right sized hole
You mentioned that it should be “Something stout enough a truck won’t crush” So I assumed that trucks are using your drive…?
yeah the garbage truck rolls over that spot every week and the heating oil guy sometimes so thats why i got nervouse about crushing something. lincolnshire you pretty much got it about digging under the asphalt. still nobody said what size concrete box knocks out for both 3 inch and 4 inch pipe tho, and if they sell a metal grate top thatll take a truck
We’ve not talked about that because we do not know what is available in the US market. Surely it is a simple matter of checking US hardware stores on line?
Sounds like you are trying to build a French drain after all.
Here’s another thought.
I’m guessing the asphalt is impermeable - hence the standing water where there is a dip.
Rather than the effort (and its a lot of effort) to dig out a hole a few feet wide and a few feet deep - through asphalt and hardcore underlay. And then dig out a trench to put the drainage pipe. All of which is a ton of really hard work probably requiring fairly powerful tools. Instead just drill some holes through the asphalt - probably 2-3 cm diameter (an inch or so). Half a dozen or more at the deepest / lowest part. Fill with small gravel. Most likely job done.
Yes a “trench” drain with a grate cover rather than a French drain is required. I’m guessing you’re trying to buy a kit online rather than getting professional advice and that’s why you posted. But UK specs will be different from US sizing.
that will just erode and displace the asphalt over time - the water needs to run off to a drainage channel into the sewer or some other drainage channel such as an irrigation system for plants
he is in england if you check under his profile
Everything else he’s said points to the US though, including posting in the middle of the UK night.
Seems to me there is some confusion if the guy has a three or four inch pipe 
Surely, anything like a box will just collapse when a truck (lorry) rolls over it?
However, there is some grating that you can buy that runs down the side of the drive and takes away the surplus water.
