These little babies made installing James Hardie lap siding a breeze. I've never installed lap siding before, but with my nailer and these gauges, I was able to side my 16x24 shop much quicker than I ever thought possible.

Installed Hardie fiber cement siding on my single car detached garage (using HZ5 clapboards), these gauges made it possible for me to do all of the work myself. Working from bottom to top, you simply slide these under the previous course of clapboards, lock them in place by raising the lever upwards, then sit the next course of siding in the notch in the gauges...it sets the reveal perfectly and holds them so you can nail down the clapboard.

There are a few tricks to using these. Do not try to raise the levers all the way up when locking these in place...halfway up is enough. If you're using HZ5 siding like I was (which has a beveled lower edge) , it's possible for the clapboard to slide out of the notch that's supposed to hold it in place...this happens if you tighten the lever too much, which causes the gauge to pull away from the wall. Just be mindful of this while working and you'll be fine.

I'm going to ding these 1 star on the review simply because with a few tweaks, the minor issues with these could be fixed to make them work flawlessly.

I can not imagine hanging Hardi board without these tools. Makes it an easy 1 man operation. The only down side is they're a composite plastic, not steel. Pay more to get those if you use them a lot. However, these performed well!

We are building a house and decided to install the hardie siding ourselves. I can't imagine trying to install it without these! This was our first time tackling hardie siding, and these made it so easy. We try to be DIY-ers if we can, and at first I was so nervous about attempting the siding installation. Now that it's complete, we have gotten complements on how professional the siding job looks. My only complaint is the same as many other reviewers, the siding can slip behind the tool.

This made putting up Hardie Plank siding pretty easy. You have to learn to adjust the lever to your desired angle or degree of tightness but it did not scratch the previously applied boards it was resting on and it slid on easily. Great product.