Checking straightness over 7metres

[Pete.]

A string line pulled tight would be good enough especially given the method of construction suggested. Anything 7m long, made of metal and light enough to handle is going to bend like a noodle anyway but unless you're laying the base for an indoor bowls green it'll give you perfectly acceptable results . Aluminium straight edges bend with the heat from your hands, it's just that for screeding tolerances it's not noticeable.

 

[normspanners]

i used a Watts water gauge

What Watts does a watts water gauge want when working in wet weather??

 

[gordon stephenson]

No watts at all required, wet or dry, lovely simple bit of kit, no outside source of energy needed.Just H2O and a long pipe, Managed to find a photo on the internet, they probably have some fancy expensive electronic kit now, but these are foolproof/reliable and no batteries etc required.

 

[Turbo]

i use one of these for work .there brill for leveling sockets and for marking and putting recessed lights in ceilings http://www.tool-net.co.uk/p-413371/...pls180g.html?gclid=CL-D0sWT7cYCFSgGwwodhdgGwg

I've used the dewalt version of that in a previous job installing roller shutter doors. Incredibly useful item, always keeping an eye out for a used one.

 

[normspanners]

When we set up rally cars we use 2 lengths offishing line stretched tight down either side to form a 'box' it doesnt sag and keeps itself tight, because of the stretch.