laser levels

[Bill Wright]

Anyone got any advice re the choice of a laser level suitable for installing a suspended ceiling?

Bill

[Andy Burns]

Going to be a bit fiddly getting a tripod mounted one up that high, some can be magnet mounted to a chunk of metal screwed to the wall.

[Chris Hogg]

I have one; bought for getting the surround of a pond level before filling it. But I could only use it at dusk because where the red spot shone wasn't visible in normal daylight, let alone bright sunlight. Probably not a problem indoors, but worth bearing in mind if you might ever use it outside; get a good bright one. (Having said that, there might be an elfin safety limit on the laser power in these things).

[Andy Burns]

Or if you can justify it, a green one.

[John Rumm]

One of the wall mounted, self levelling ones that project a line round the room (rather than a dot) seem to be favoured for this application.

[Andy Burns]

But when buying one consider whether a cross laser, rather than line laser might come in handy for any other jobs later ...

[Tim Lamb]

In message , Chris Hogg writes

I have an ancient red spot level. OK in normal daylight if you use a white target.

For levelling the pond surround I made a triangular raft from three empty plastic containers and had a projecting rod to reach over the bank for the level. Of course you need to pond to be partly filled with water:-)

>

[Tim Watts]

Professional ceiling fitters I've seen use a heavy rotating dot laser bolted to the wall in one corner of the space. This gives a very bright line to work to.

[GB]

Just to satisfy my curiosity, why does a pond surround need to be level?

[Huge]

Otherwise the liner shows on one side. It looks terrible.

[RobertL]

The ones that produce a line, rather than a dot, are generally less bright.

Robert

[RobertL]

If it's a formal surround then it looks odd if it is at a slight angle to the surface.

The raft is a neat idea:-)

Robert

[Chris Hogg]

To prevent the water flowing out? :-)

The pond is on a gently sloping site. In order to be sure that there was the same freeboard all round and that the water didn't flow over the lower edge, I had to excavate about 18 inches on the uphill side, and build up about 12 inches on the downhill side, before putting in the liner etc. The pond plus adjacent bog garden is oval, long axis aligned with the slope, about 22 ft long, and I didn't want to trust doing it by eye.

[Dave Liquorice]

A line generated by a diffraction grating reduces the light level. One with a spot that is rapidly scanned around the room (rotating spot) doesn't suffer this.

I can't decide if self levelling is a good idea or not. When I used a rotateable laser level to get a line for a wallpaper border half way up a wall at window cill level. True level wasn't right, align it for one end of the cill it would be wrong at the other. With a suspended ceiling this probably isn't an issue as you're not trying to align with anything and any error relative to, say, the top of a door frame is likely to be small/unoticeable.

So basic spec: brightest laser(*) and green isn't bad idea, rotating spot, self leveling, tripod and wall mounting.

(*) Look at the class. I have a Class III red laser pointer, you can see the spot but it's not wonderful. And a green Class IIIa, that is rather bright. It's right at the bottom of the Class IIIa range so just over 5mW but powerful enough to cause injury if looked at directly (or a hard reflection) and eye protection is recommended for diffuse reflection. It's bright enough for motes of dust to glint in the beam. Fresh batteries and you can detect a little bit of warming on thin skin... Visible beam outside on a *clear* starry night, great for pointing at which star/satellite you're looking at.

The Class system has been revised and now uses arabic numbers rather than roman but the power bands are very similar. I think the regulations have changed to prevent the general sale of Class 3B (might even be Class 3R) or higher laser devices.

[Dave W]

A long straight item suspended by two equal strings from a single point would hang level, removing the excuse for buying a laser level.

[GB]

Thanks for explaining. I'd have tried a bit of wood with a spirit level, but that wouldn't really work for 22 feet.

[Harry Bloomfield]

Bill Wright explained :

The old and perfectly accurate way was to use a water level - nothing more than some narrow bore pipe, either clear or clear pipe at the ends, filled with water. Coloured dye makes it easier to see the water level and ensure there is no trapped air in the pipe.

[Harry Bloomfield]

Dave W brought next idea :

But where is the fun in that?

[Chris Hogg]

I tried that with my pond, but for reasons I never understood, it didn't work. Either there was an air-lock in the pipe, or it was blocked in some way, but the water-levels at the two ends were obviously different. That's why I got a laser level.

[Dave W]

Indeed.