How to align screws to hit purlins through insulation

[d000hg]

Sorry about that I forgot that image included the ceiling, apologies for confusion.

Actually the photo is a little different to ours, that has purlins angled to the roof whereas ours are vertical with the top angled to fit the roof. Only just noticed that

 

[Tigercubrider]

with you now on the structure. I was looking at the first diagram.
But you could drill pilot holes so that the ceiling is relatively safe, but using a jig should avoid that.
You can make a jig really big to ensure accuracy, by adding a baseboard

 

[d000hg]

with you now on the structure. I was looking at the first diagram.
But you could drill pilot holes so that the ceiling is relatively safe, but using a jig should avoid that.
You can make a jig really big to ensure accuracy, by adding a baseboard

You reckon custom-building one to the fixed angle needed might work better? Those products look nice but perhaps a little flimsy for a large job - that's why I wondered if you can get a pro drill with one built in or a more substantial version.

I can't see making one is too difficult and worth the time saved.

 

[Tigercubrider]

I would have thought that a baseplate with a vertical that is backed by a couple of triangular braces would work, the "vertical" could be set at 15 degrees.
Depending on the drill you could screw a couple of rails to the "vertical" as guides or include another bit of timber to create a corner that acts as a guide.
stick a sheet of sandpaper to the base for grip (or rubber)

I would also knock up a trial bit of "roof" on the ground for a test - just a pair of rafters 50cm apart at 15 degrees angle off the ground and a deck made of ply offcuts

 

[^woody^]

Yes, all this talk of making jigs and rigs gave me an idea.

I've phoned up my mate Dougal McVertical, and he said if you can get the shed up to Aberdeen on Saturday, he can drill you some vertical holes before he knocks off for chrimbo.

 

[datarebal]

are you in the trade

No i am a car park shopping trolley collector

pu adhesive pir to a bituminous vcl torch down top layers.

 

[Leofric]

This has it all - aggro, sarcasm, woody p i s s taking , original poster getting arsey - Merry Christmas to all

 

[^woody^]

My work here is done.

 

[Notch7]

Ive been involved in building dozens of warm roofs, we use 180mm screws and screw into 45mm firrings.

Earlier this year I built a garden office with 18mm OSB, 120mm celetex, 11mm OSB, firrings.

Out of say 250 screws maybe 6 missed the firrings.

I would have assumed your purlins are perpendicular to the pitch of the roof, so the screws would be 90deg to the deck.

 

[Ian H]

Do 1 screw at each end of the purlin then pull a string across to line all the others up.