Mot Pit

[jez vinnicombe]

Hey all, glad to be a member of the forum now. been watching it for a while.

Now ive taken many projects on before, but this one is new to me. ive built many walls for myself and shed bases.

im building an MOT pit for my new garage. its 7.5m long, 2m deep and 1m wide, thats the finnished opening. now ive been told by different builders different ways of blocking it but now im in a mess. i was going to use 215 hollows filled after but the cost is very high and after paying 40k for the test lane im now on a very tight budget. another builder told me its perfectly acceptable to use 140mm dense all the way up with 3 piers. now this is more within my budget however im unsure itll hold back the ground?. my ideal plan would be

6-9" base slab laid at 8mtr x 2mtr
140mm dense blocks all the way up to 1.8mtr then my angle iron for pit jack on top.
all blocking would be formed in a single loop so corners tied in etc
piers at every 2 mtr or even spread.

do you think the 140mm will be ok?? some old timers have said they used to build there old pits with aerated blocks and there still in use today.

cheers all!

 

[freddiemercurystwin]

There was a thread in projects I think with someone detailing their pit build, worth searching for, maybe a year or so back.

 

[^woody^]

9" wall in English bond with engineers or semi engineers on a 6" concrete base.

But if you are within influencing distance of the building's foundations and your are going deeper than them, then the bottoms of the walls need thickening.

 

[Mottie]

When ours was done years ago, a reinforced cage was built, the pit area was shuttered up with ply, this was coated on the outside with some kind of release agent, heavy, heavy blocks of wood, lots of 'em, were placed between the two sides to stop them collapsing and then the concrete was poured in one go. We left a space for a couple of I beams along both edges for the jacking beams to roll on. The steps were formed afterwards. Don’t forget to run a tube for the electrics to go through and a sump in the bottom. Make sure you get the floor dead level if you’re going to mount your headlamp aligner at the front of the pit.