Laser Level/Builders Level...

[Mulberry View]

We have a generous plot (around 0.55 acre), on a slight slope. I'm not yet sure how much of the groundworks I'll be doing, but I plan to be hands-on throughout the whole project, including with the landscape garden.

 

Do I ought to consider buying a Laser Level or similar? If so, what sort of thing would be right for this project?

 

Any advice is appreciated.

[Russell griffiths]

Outside rotating level with a receiver 

inside any laser that does two different planes at the same time. 

[Mulberry View]

1 minute ago, Russell griffiths said:

Outside rotating level with a receiver 

inside any laser that does two different planes at the same time. 

 

Which rotating level is that? What sort of money?

 

[Russell griffiths]

Just now, Mulberry View said:

 

Which rotating level is that? What sort of money?

 

It’s years old, I would expect to pay £450 for a new one. 

[nod]

I’ve used Hilti green lasers for years 

One feature I find invaluable is the scanning feature Click the receiver three times and it will find parallel 

Up to 100 meters 

Invaluable in bright light 

[saveasteading]

I strongly recommend learning the principles of levelling. I don't mean you have to use an optical level, but you should know how they work.

Laser levels are doing the same thing

 

I used to ban lasers because everyone thought they were infallible and so everyone used them and mistakes were many.

I have given up banning them as nobody except me seems to be able to use an optical one. 

But what do you know,  this week we have a block wall that is 8mm different on 2 parallel walls 5m apart,  even though the bricky used a laser. 

Not a good start for a timber frame.

 

 

[BadgerBadger]

Rotating lasers are great but more expensive.  I decided to make do with a simple DeWalt cross hair laser with a receiver and staff.  Primarily for "coarse" leveling of access etc. but it's been absolutely invaluable for checking levels as contractors are progressing.

[Conor]

2 minutes ago, BadgerBadger said:

Rotating lasers are great but more expensive.  I decided to make do with a simple DeWalt cross hair laser with a receiver and staff.  Primarily for "coarse" leveling of access etc. but it's been absolutely invaluable for checking levels as contractors are progressing.

I have exactly the same, and made my own staff from a length of ceiling channel section and timber batten. Invaluable for things like drainage and setting out slabs. Half the price of a rotary setup but less range and coverage but does the job for the likes of us.

[MikeSharp01]

Ours is a Leica Ruby 620 (Might get a green one next time) but is has been a great buddy. It can be up to +/-2.2mm out over 30m so it you need better than that you are into total station country.

[Jenki]

You can pick up a dumpy level (optical) for 50/60quid, a cheap tripod and staff for similar.   not difficult to get to grips with and very accurate.  only issue is its a two person job.  

The rotating levels and receiver can be used by one person. 

This is my approach, I put a master stake in the ground and set some other slaves stakes dotted around at the same level with the dumpy level. Then use the laser on my own to do a lot of the setting out, I can always check the laser against the master and slaves stakes.  Once happy I then re check with the dumpy level. takes a bit longer, but not as long as pouring concrete at the wrong level.

[MortarThePoint]

I've more lasers than make sense to be honest (no sharks with lasers on their heads though). I bought a cheap rotary laser from China (see red one below, £175 at the time) but I wouldn't recommend it as it had an issue straight out of the box. I was able to fix it and have tested it's accurate. Like with a spirit level, it is important to know how to regularly check this sort of device as you don't want to find out later that there is a problem. When I have done surveying I have repeated the process twice with the rotary laser in two different places and checked that the sets of readings agree. As I am a massive geek, I have also used homebrew RTK-GPS for surveying which works nicely for plan, but not so well for elevation.

 

There are various non-rotary 3D lasers that have a pulsing feature. The pulsing allows you to use it with a detector when light levels and distance are too great to see it by eye. I've never used the glasses which could help under that situation. I have a Huepar one which supports the pulsing. I've never used that feature, but at dusk or in the dark it throws the laser a very long way. I thought this laser was good enough to by a second one when I smashed the first falling off a ladder. I got it from Amazon for £160 but it's now £145 (https://amzn.to/3mSTxaV _{note that's an affiliate link but doesn't cost you more}).

 

 

[dpmiller]

^ I've the green version of the rotary above and it's very good.

[Thorfun]

51 minutes ago, MortarThePoint said:

I have a Huepar one which supports the pulsing. I've never used that feature, but at dusk or in the dark it throws the laser a very long way.

 

+1 to Huepar. it's been very useful and relatively inexpensive. the brickie and I used it to set out the coursing blocks in pulse mode for our timber frame and the TF company said it was bang on. and I used it at dusk for the guttering and downpipes and everything was level and fits!

[Tosh]

I picked up an optical level/staff/tripod from auction quite a few years ago, iirc £75. Been great but purchased a 360, 3 plane green laser and receiver last year with obvious benefit that you can do it alone + the 2 extra vertical projections. The latter have been useful for checking plumb and alignment of existing steel building plus setting out stud walls in future. You could get away doing your land survey with optical level but I think the extra benefits of the laser later in the project should be worth thinking about.

[saveasteading]

17 hours ago, Jenki said:

not difficult to get to grips with

Says you who understand it.

I have trained/tried to train several people but they either understand it or they don't. 

Using a laser for small building works is really just carrying a set level (probably set by someone else) around to mark the same level elsewhere. Easy, and no excuse when it goes wrong.

 

17 hours ago, MikeSharp01 said:

+/-2.2mm out over 30m

is rather poor.

It doesn't normally matter if the machine is placed centrally and used over a short distance.

 

The fundamental principle is whether the machine is describing an exact horizontal circle, or is pointing up or down a bit. If the distances are all the same then the error cancels out.

 

to check a level:

Place it centrally between two solid points, and measure the height difference. 

Then move the machine so that it is close to one of the points and distant from the other. Read the height difference again and it should be the same.

If it isn't then the machine is not accurate and needs adjustment if this is provided for.

[MortarThePoint]

8 hours ago, saveasteading said:

On 16/06/2022 at 06:48, MikeSharp01 said:

+/-2.2mm out over 30m

is rather poor.

 

I'm not  timber frame person, but +/-2.2mm over 30m doesn't sound poor to me. That means one end of a 15m house might be 2mm lower than the other. What needs to be better than that?

[saveasteading]

9 hours ago, MortarThePoint said:

What needs to be better than that?

Ignore me, I come from a discipline where we had to measure to much tighter tolerances. After surveying many km we were supposed to be just a few mm out.

My view is that if the level is accurate then that is one possible error removed.

 

I acknowledge that on a small house that will usually be ok.

BUT starting from a low accuracy at its best, I would worry that it loses more accuracy over time.

AND as stated above, it is essential to use equally distanced sightings or it will be 3mm out, to which add other tolerances, and you get the 8mm error our groundworker made last week.

Also for long runs such as drainage might be, it can matter.

[Tom]

I recently bought a (second hand) high precision altimeter https://www.groundscare-products.co.uk/ziplevel.htm#buyonline

Highly accurate and simple, quick and easy to use - or so it seems. Haven't actually used it yet...

[Gus Potter]

On 15/06/2022 at 23:58, saveasteading said:

I strongly recommend learning the principles of levelling.

One easy basic check is called a two peg check.

 

@saveasteadingAgree, just because it has a laser in it and some spec does not mean it works just out the box or a week or two after, or it after it has been dropped.

 

Don't get fooled by the "self levelling" sales pitch. For DIY recommend to learn this basic check on your laser for horizontal levelling. No matter if you have an instrument costing £100.00 or 10- 20K you need to know how to do a basic check.

 

Set up two posts in the ground 30.0m apart, measure carefully (use a steel tape if you can as plastic / fibre ones stretch) and try and do this on level ground. If the ground is not level then it gets a little more comlpex but can still be done. Sit the laser 10.0m from one post, run it and mark the level on each post. Move the laser to 10.0m from the other post and do the same again. The height of the laser will not be the same as the ground won't be level even if you don't change the height of the tripod/ instrument on top (called the height of collimation). Measure the distance between the marks on the two posts. If they are not the same then your laser is off and thus what you build will be off... but by how much?

 

If you have a laser that also does vertical lines then sit it next to a wall. Drop a plumb bob down the wall and sit the plumb bob in a bucket of water to help reduce it swaying in the wind. Check the distance the laser to the wall top and bottom. Check the distance of the bob line from the wall and you can then work out if your laser is projecting accuratly in the vertical direction.

 

Now at 30m you always get a different reading. If anyone is interested I'll show the maths (caveat..would like some real numbers from you to work with) and, how you can cross check this with the declared instrument accuracy and what you need it to do. This will suit most small domestic applications but for larger projects we need more attention to the details and use other techniques. At the high end even the temperature of the air for example has to be measured.

 

I did some levelling a while back in a tall building and the thing was going all over the place, nothing wrong with the level, it was the building swaying in the wind.

 

If you are going to be spending money on your project then 10 -15 minutes checking your kit is a small price to pay.

 

 

 

 

 

 

 

Edited June 17, 2022 by Gus Potter
added a bit non level ground

[SteamyTea]

8 hours ago, Gus Potter said:

If anyone is interested I'll show the maths

Many a happy minutes doing Bowditch Corrections.

 

Found this.

https://civilblog369.blogspot.com/2019/01/levelling-surveying-civil-engineering.html

[MortarThePoint]

13 hours ago, Tom said:

I recently bought a (second hand) high precision altimeter https://www.groundscare-products.co.uk/ziplevel.htm#buyonline

Highly accurate and simple, quick and easy to use - or so it seems. Haven't actually used it yet...

 

Interesting, that webpage is a bit light on how it works but is the 'wire' connecting the two units actually a tube full of a liquid and it measures the pressure difference between the two sealed ends?

 

Very handy it doesn't need line of sight.

[MortarThePoint]

14 hours ago, saveasteading said:

Ignore me, I come from a discipline where we had to measure to much tighter tolerances. After surveying many km we were supposed to be just a few mm out.

My view is that if the level is accurate then that is one possible error removed.

 

Interesting. I've always been impressed by the Napoleonic era triangulations.

 

Curvature of the earth would render a laser level 3mm out at 200m I think. Unless the world is flat of course 🙂

[SteamyTea]

24 minutes ago, MortarThePoint said:

 

Curvature of the earth would render a laser level 3mm out at 200m I think. Unless the world is flat of course

Or your site is on a slope.

Or you have @saveasteading builders.

Alternatively, bury head in the sand and hope for the best.

[Tom]

1 hour ago, MortarThePoint said:

 

Interesting, that webpage is a bit light on how it works but is the 'wire' connecting the two units actually a tube full of a liquid and it measures the pressure difference between the two sealed ends?

 

Very handy it doesn't need line of sight.

 

"ZipLevel works by sensing minute pressure differences within a pressurized gas/liquid system." - doesn't look like it's new technology, used to be called the Stanley Compulevel apparently. The thing needs re-charging every 3 years or so, but I guess even laser levels need recalibrating.

[saveasteading]

On 17/06/2022 at 19:39, Tom said:

high precision altimeter

I got one of them for the business. (different make, same principles).

 

The great advantage to me was that it could be used single handed, so I could check levels after the works were over and distractions gone.

Also it is great for going round corners and up stairs, as the cable goes where you want it. That would be so much more work, (with change points)  with a traditional level.

It can measure several metres height difference so is good for deep pits, banks etc.

 

Against it... With the trailing pipe full of pressurised oil, any damage is terminal, and it can't be used where vehicles or even pedestrians may pass.

In practice, I found I had to recalibrate often, especially if the sun was out, as it would read wildly wrongly when it got hot or cold.

Nobody else in the business had the slightest interest in it, so it seems that it works for you or it doesn't.

 

So jut watch that last issue and you should be fine.