I am building an CEB (like adobe) home and would like to buy a laser level to help make sure the top course is level. There is no roof yet, and this will be outside, and in the sun. The house is only ~20' x 20', so the furthest the laser will have to travel if we put it in the center is something like 14'. Will most rotating laser level points be visible at this distance? I've seen multiple different mw power levels for lasers. How far is each visible outside in the sun?
The laser beam itself will barely be dissipated by the sunlight, check the specs on each device for their range. The difficulty seeing the laser can be attributed to the sunlight flooding all* light spectra/frequencies as well as sensitizing your eyes (or camera white balance) to light. Creating a shadow with your hand near the laser point on the wall should easily reveal it. If you can find/afford it, a green laser would work better for outdoor applications, the light frequency is further away from infrared as well as they are typically stronger.
* "All" is relative to visible frequencies (and a few invisible ones) but for cases of visible light by human eyes, the near red frequencies are visibly flooded heavier due to infrared being so close.