Forum: Site Works
Topic: Use a rotary level
started by: Mistajayljul
Posted by Mistajayljul on 26 Feb. 2018,23:12Can anyone help me out
Iím looking to use a rotary level
On the †plan you can see +10.00 at the top of the plan
Iím trying to work out how I can reach this on a staff and all the other heights on the drawing
We are wanting to dig the site area out which will be +5.00
I think I could pretty much get ther by using the +6390 and digging down 1390 and come off level by this, but Iíd like to know how to use a level
Also wher I should position the laser in the first place
Can anyone advise please
< Plan >
Posted by digerjones on 26 Feb. 2018,23:30You need to settle the level up where it will reach all the site.
Bang a peg in or mark a wall or something like that for your datum mark and always use this to start your levels
Posted by Mistajayljul on 27 Feb. 2018,00:00Thanks
Can you tell me how you would get to read the same levels as on the plan?
You can see where the house will sit, that the area is at +5.00
But Iím not sure how to get to read that on the staff
Itís probably really simple but Iím struggling to get my head around it.
Posted by digerjones on 27 Feb. 2018,21:03Sorry I've got a laser level but can't help you with this one. Like you say probably very easy. Hopefully someone else will come along to explain to both of us.
Would imagine there to be a datum level and the figures on the plan are + or - from this.
Posted by Tony McC on 01 Mar. 2018,11:48Set up your level in a position that can clearly see all relevant level points on the site, or as many as is possible. Iíd suggest somewhere a metre or so from the top right corner of the house, and set as high as you can comfortable reach, even if stood on a box, say 2m (ish) above GL.
Take a staff reading at your datum point. I donít know what points are in existence, but, again for argumentís sake, letís assume the footpath at the front of the property is extant, and has the level shown on your plan : 3190
Knock in a masonry nail at this point so you can find it again if necessary.
Letís say, for argumentís sake, that the reading from the staff on this datum point says 1950
You know the plan has this point as 3190, but your staff says 1950, so you would need to add 1240 to the staff reading to get the same result.
Now, if you move the staff to a peg marking, say, the lower RH corner of the building, you know that the level here is supposed to be 5000 but you also know that your level is giving readings at 1240 below the plan levels, so you need to set a level at this point/peg that is 5000 minus 1240 = 3760
When you get a staff reading of 3760, you know that, in relation to your original datum point on the footpath, this point/peg is 1810 higher (5000 Ė 3910)
Your staff reading at datum was 1950. Add the 1810 rise that is required: 1950 + 1810 = 3760. You need to set the peg to a level read from the staff of 3760
Now, you can use the same technique to establish levels elsewhere on the site.
Does this make sense?
Posted by Mistajayljul on 03 Mar. 2018,06:17That does indeed make sense
Thanks so much for the explanation