Don't let anyone kid you hanger bolts shouldn't be used on either tiled or slate roofs as they are often a better choice when compared to one size fits all tile or slate hooks.
Next time you fit plain tile or slate hooks mount the rail before laying the lap tile and give it a tug and see how much travel you get. Tell me that's not scary. How well will they perform in high winds? Not very well if my experience with Hilti's plain tile hook is anything to go by when at 900mm centers they were lifting and breaking the lap tile on the bottom rail at the corner of an array. You wont get any lift using hanger bolts.
All the attempts I've seen at weathering slate hooks to date fail to take account of the very real risk of the array lifting under high wind loads. If I were to use slate hooks then I would replace the whole lap slate with lead to at least reduce the chance of damage to the slates surrounding the hook if the array lifts.
No assessor can fail your installation because you have chosen to use roof hanger bolts in place of hooks on you install, they're approved. They are easily weathered and you won't be reducing your clients roof to little more than a sieve. If you were worried about rain entering around the bolt (you just as well worry about wind driven rain under hooks) then fix the bolt near the lap tile and fit a lead/ali diverter.
Ding ding.
Next time you fit plain tile or slate hooks mount the rail before laying the lap tile and give it a tug and see how much travel you get. Tell me that's not scary. How well will they perform in high winds? Not very well if my experience with Hilti's plain tile hook is anything to go by when at 900mm centers they were lifting and breaking the lap tile on the bottom rail at the corner of an array. You wont get any lift using hanger bolts.
All the attempts I've seen at weathering slate hooks to date fail to take account of the very real risk of the array lifting under high wind loads. If I were to use slate hooks then I would replace the whole lap slate with lead to at least reduce the chance of damage to the slates surrounding the hook if the array lifts.
No assessor can fail your installation because you have chosen to use roof hanger bolts in place of hooks on you install, they're approved. They are easily weathered and you won't be reducing your clients roof to little more than a sieve. If you were worried about rain entering around the bolt (you just as well worry about wind driven rain under hooks) then fix the bolt near the lap tile and fit a lead/ali diverter.
Ding ding.
