When i installed my sloped tripod I missed 2 trusses. I then went in the attic to unscrew the 2 screws from inside with vise grips then added 2x4 backings which I attached to trusses on both sides. Finished removing the lag screws on the roof then used brand new ones to replace. While it would have been way easier to unscrew them from the roof, I wanted to avoid 1 roof visit...

If I had to do it again I would probably ask someone to be in the attic while I drill preholes for the lag screws. This way if it's not at the expected place the helper can put a backing in place before you're set to screw.
You may or may not find it hard to find trusses. Depends on how steady the trusses go and it doesn't help that you're trying to keep things level !!!

Since I have a pyramid shaped roof an eave mount would have been impractical, not giving me enough height. If I had a V shaped roof I would have done an eave mount close to where both slopes meet without hesitation

can't ya locate the truss by looking for where ur gutter spikes are?
then snap a chalk line up the rise of the roof. Properly hung Gutters are always spiked in to them. In a pinch ya can also find em by lookin above any sofit panels. Do the same thing, snap a chalk line on the roof from the center line of them up to the peak of the roof, so ya don't miss.
If I'm a young guy who's gonna be around for a while, say 20's,30's,40's I might be hesitant with a tripod on my roof.
If I'm an older guy, nearing retirement with a fairly new roof, I probably wouldn't worry about it. Let the next guy worry about it, since it's not likely I'll even be around to replace that roof the next time. Run in to a problem ya can always tar it up:)

majortom, that's similar to what I've always recommended here (http://www.digitalhome.ca/forum/showpost.php?p=486802&postcount=222): measure the joists from the INSIDE, then pop some very small test holes for locating the joists. No big deal because you plaster the holes with roofing tar and no leak ever happens.

xilbus, relax about leaks. Do it right with tiny test holes and there is no problem.

Gutters (eaves troughs) are installed after the house is finished so the spikes just go into the wooden eaves and likely don't line up with the trusses.

I'm going to be facing this within the next few weeks. Any advice for cedar shakes? I too am nervous about anchoring into the roof, and the cedar shakes makes me even more uneasy.

How old are the cedar shakes? They get brittle with age and if you aren't very careful they can break just from walking on them.

Any advice for cedar shakes?Yep, splitting them would be my worry too. I would purchase four or five cedar shakes first and then during the installation replace any split ones as necessary. You might even want to just install the new ones at the appropriate points beforehand because you should be able to gently drill through a new one in a few drilling steps (increasing bit size from very small to the correct size) without any splitting.

They were getting brittle but I oiled them last fall to try and make them last. Walking on them wasn't too much of a problem a couple of splints here and there but only a couple mostly on the south facing side.

I may investigate the possibility of using an eves mount. there is an upper roof with eves that should hopefully not impact my height too too much. If that doesn't work then I will have to plan to purchase some extra replacement shakes wasn't really planning on that. Thanks for the advice.

I like stampeder's idea of drilling through the shakes in increasing sizes. I would also suggest using close to clearance sized holes in the shakes (and then fill it with tar before installing the lag bolt to prevent leaks) and only use a pilot sized hole for the truss. An eave mount would likely be a better option though.

I guess I'm thinkin of common rafters, which extend beyond the outer wall, making up the eaves which let air in to the attic. the end of the rafters are then trimmed off, with a facia board nailed on to it. The gutters are spiked thru the facia, in to the end of each rafter not the facia alone which is only like 1 by . Least that's what I'm used to seeing around here.
I'm certainly no carpenter, so maybe just using the wrong terminology...

I'm surprised there's any roofs out there still made of cedar shake.
Those get torn off and replaced with plywood, then standard asphalt shingle around here.

majortom, maybe you are right. I was just thinking that after the fascia and soffits are installed, it would be difficult to determine where the rafters or trusses are (around here at least, houses don't come with gutters and thus are installed after construction is complete), so many gutter installers may just hammer into the fascia.

Regarding ceder shakes, they are often used on the west (wet ;)) coast where the more durable western red cedar is redly available and there is less concern about ice damage. Even there they are becoming less commonly used since 2nd growth ceder isn't as durable as old growth.

roger, I hear ya. I'm just thinkin if they weren't spiked in to each rafter properly, they'd never stay up. I think a couple of adjacent soffit panels can be removed just enough to take a quick peek and popped back in place. Ya may need a few extra white aluminum trim nails to nail em back in place though.

good morning guys,

its a sunny morning in aylmer, wish me luck, going up in 30 minutes to install my 5 foot tripod with the HD stacker :-)
going to beat this no pbs thing in Gatineau hehe

ill post back once its done

if you have the time, take a couple pics during and after to show your hard work...stay safe and good luck with the install...

guys the install is finished

got the tripod up on the roof and tried to centre it as much as possible, then mesured from the centre to the feet.
got into the attic , did 3 pilot holes besides the studs that i wanted.
the pilot wholes were 1 and a half inch from the centre of the studs so by then it was really easy to find the studs.

whent back on the roof with the tar patches and tar tube gun and bolted everything into the 3 studs
for some reason i cant post pics so heres the album, ran out of bats on the camera on the roof.

http://www.digitalhome.ca/forum/album.php?albumid=746

Great job xilbus - too bad about the batteries running out! :D A gently-sloped roof like yours is a pleasure to work on.

Thanks Stamp the roof angle is too wide for a eaves mount so my last hope was the tripod or a tower and my father in law kicked me in the but to get the tripod up
he said if theres a vent there that doesnt leak with the right tools the tripod wont leak ither,

so its a two story house with a 5 foot tripod plus 7 foot galvanized fence post plus 3 feet for the rotor mast. im saying around 25 or 30 feet.

Aren't the mast sold at The Source galvanized?

They should be. My only issue with those is the fact that they're extruded tube with relatively thin walls, so they just aren't as durable as galvanized pipe. Mind you they're a lot lighter, so the situation at hand might dictate using tubing.

As always, don't mix metals that are directly in contact due to the risk of galvanic corrosion.