I need to drill 16mm diam holes in a reinforced concrete slab.
14 holes each 150mm deep.
The holes will be used to resin in anchor studs, and then right angle straps are being bolted to slab ... the vertical portion of strap will then be secured to vertical studs of timber frame walls.
http://tinyurl.com/87wnxa
The main thing is here is that the holes in the 10mm thick galv straps are pre-made and fixed, so I can't allow the holes I drill to wander off line.
I have an SDS drill and a new 16mm bit.
When I have drilled SDS holes before they tend to wander about until a cm or so into the material.
Any tips on doing this ....
some options I have thought of are :
#1 use a non SDS pilot hole, before using SDS drill ... although I read on DIY forum that SDS bits should not be used with a pilot hole, due to way they work.
#2 bolt straps to vertical studs first and drill through the clearance holes - risk here is damage to the galv finish, and this is an external job so need the protection.
14 holes each 150mm deep.
The holes will be used to resin in anchor studs, and then right angle straps are being bolted to slab ... the vertical portion of strap will then be secured to vertical studs of timber frame walls.
http://tinyurl.com/87wnxa
The main thing is here is that the holes in the 10mm thick galv straps are pre-made and fixed, so I can't allow the holes I drill to wander off line.
I have an SDS drill and a new 16mm bit.
When I have drilled SDS holes before they tend to wander about until a cm or so into the material.
Any tips on doing this ....
some options I have thought of are :
#1 use a non SDS pilot hole, before using SDS drill ... although I read on DIY forum that SDS bits should not be used with a pilot hole, due to way they work.
#2 bolt straps to vertical studs first and drill through the clearance holes - risk here is damage to the galv finish, and this is an external job so need the protection.