Straight line for laying blocks when it’s too windy for string?
I’m about to start laying four courses of CMUs for the stem wall of a simple rectangular house’s foundation.. It’s been very windy here and will continue to be for another few weeks. On the one calm day we had, I projected the string lines for the outer edges of the house downward, drawing lines on the surface of the footing itself so that I would have a straight, accurate line when it’s windy, but as I plop mortar down to lay each block in the the first course, those lines will get covered. Pulling the strings extremely tight (with a bar clamp) reduces their curvature in the wind, but they still curve by as much as 1/2″ off, especially as the wind typically blows perpendicular to the long side of the house. Waiting for calm days when I can work on it could easily delay me by a month. Is there some way to get an accurate guideline for a straight first course of blocks when it’s too windy for string?
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Replies
Laser.
Yep, take a look at lasers for tile layout. PLS is my favorite brand.
Thank you, Malcolm and David. I had thought about a laser quite a while ago and then forgotten about it after it seemed as if one I could see in daylight would be too expensive, but you prompted me to look again, and I found the following, which is described as indoor/outdoor, but has conflicting reviews re visibility in full daylight. I imagine I could get by if I could see a spot in full daylight. Does this look suitable, or if not, what is a realistic minimum to pay for one that I could use in full sun?
http://www.lowes.com/pd_591021-16878-64130___?productId=50246769&pl=1&Ntt=laser
Set up a tarp for shade? That's problematic in windy conditions too, but maybe possible.
I am sorry I don't know how to judge what product would work well in sunlight, buying from someone with a good return policy is one strategy.
Most lasers are not going to be visible in full daylight--you need to use a detector. Something like this http://www.plslaser.com/products/pls-180 would allow you to work very accurately regardless of daylight or wind. They are not cheap, but maybe buy it, use it, and re-sell it on eBay when done? If you need something that will let you check on a block-by-block basis as you go, this is pretty much your only option. The item in your link will not be useful.
Jeff,
If it's only for the first course I'd rent the laser.
Thank you, all, for your recommendations. Good to know the inexpensive lasers wouldn't be useful. I had a new idea: using concrete nails or screws or regular nails dropped into drilled holes along the perimeter line. The nails or screws would stay put and still be visible/feelable after the mortar bed is placed.
Something like that might work. I don't know how wide your footing is, but you could nail down a couple of long pieces of straight 1x4 along a chalkline (wait for the wind to stop before snapping the line), and then set the first course right against the wood before removing it. Once you have one course set along one long side, turn the corner square and continue.
Great suggestion, David; thank you.
I ended up using one straight 1x2, drilling three holes through it and into the footing all at once with a 3/16" bit, then dropping a nail of the same diameter into each hole. It held the edges of the blocks firmly against the proper line, and when I was done with one 8' length, it pulled right out to be used again for the next. If I keep drilling through the same holes in the wood to make new holes in the footing, the holes in the wood might get a little too big, in which case I'll just drill new holes in the wood. I'm glad I marked the lines onto the footing when I had a rare windless day, as it made feasible an inexpensive and easy solution.