Building a garage over boards?

Hi,

According to my property diagram of sanitary drainage, there is a board 6 inch that runs parallel and close to the one of the fence.

This location is also the driveway that has a carport.

Will I be able to build a garage on top of a board?

PS- I'm assuming a board is a sewer pipe.

 

What does the 6 inch mean?
What does the black square mean?

 

I believe "Board's" means that the pipe is owned by the MWSDB (Metropolitan Water Sewerage and Drainage Board) and you need permission to access them or build over them. There should also be a plan showing the pipes which run from your house to join the Board's network - these you can have your plumber work on.

The "6 inch" refers to the diameter of the pipe. You will often see "VC" with the pipe size which shows that the pipe is made of vitreous clay.

The black square is usually a junction or point where the household pipes enter the Board's pipes. On a proper plan you should also see the depth that the pipe is under the ground at each junction/entry point.

 

On the plan I see next to the black square number (1.2 and 1.3) and on the other plans I see 4 inch 2 and 4 inch 5. Do they mean how deep they are? What does the 5.1 mean?

 

Chances are that you are correct. On old plans in feet and inches the sign to show feet is ' and inches " - so 4'2" is 4 feet 2 inches (127cm)

 

So that is how deep the sewer lines are? or just black square?

 

It is the depth of the sewer line. They normally only measure it at these junctions . The connector may stand a little above that depth but not by much. If you see "IO" on the plan then there should be a pipe and manhole cover at ground level but that is only for larger diameter pipes.

 

Can you tell me what the 5.1 mean?