drilling joists

[Sparky_Ben]

for the above, do you's use a dedicated angle drill or an angled attachment for your cordless drill to fit easily between joists?

 

[Guest123]

I usually use a 110v makita angle drill that I've had for years.

 

[GLENNSPARK]

Make sure you dont drill joists on the middle third of the span wont you ben......contravenes the building regs see..........

 

[GLENNSPARK]

at least 50mm below the surface of the joist n all mate..........

 

[Engineer54]

Make sure you dont drill joists on the middle third of the span wont you ben......contravenes the building regs see..........

Mainly because they use long thin bits of timber as ''Joists'' these days!! Not so before 70's, ...then they were 'Real'' joists!! ..lol!!!

 

[GLENNSPARK]

My place went up in 1870 and everything in it is HUGE! Over engineered or what........but when you walk around upstairs it dont feel like a trampoline or make strange noises (unless i fart)...........

 

[MarkieSparkie]

An angle drill is not essential for this job but you drilled holes will not be at right angles to the joist with standard length augers or flat bits. To minimise the drilled angle, a flat bit extension, long series flat bit can be used carefully but not ideal. The better solution is use stubby augers, stubby flat bits or hole saws this enable right angle holes to be drilled but access can be cramped.
An angle drill and stubby auger, stubby flat bit or holesaw definitely makes access easier and allows the holes to be drilled at right-angles to the joist. It needs quite a lot of torque, power and battery capacity to drive the auger/bit/holesaw, this is often beyond the means of cheap battery angle drills. At the lowest useable level of tool is the Ryobi, 18V, One series angle drill with the large L-ion battery it will only drill a maximum of 3 x 25mm diameter holes in a 4"x2" joist on a fully charged battery and one hole on a nicad battery. If you use this tool 3 L-ion batteries is a practical minimum requirement. The Dewalt, 18V, DW960 with L-ion batteries is a better tool. The 18v L-ion Makita models are also better. If you have the luxury of a temporary mains supply then a corded right angle drill is still my weapon of choice, there is no substitute for power and torque.
Which ever method you choose to use remember to keep you holes in the approved zone to comply with Part A of the building regulations, see EGBR 10.1.1 or OSG 7.3.1 for details.

 

[SoulTy1066]

i recently bought a makita 110v angle drill, should of done so years ago... paid for its self on the first job

 

[sparkdog]

I tried a Sealey right angle attachment,the gears stripped after about 5 minutes.

 

[oxocube]

Just cut a flat bit down so it sticks out from the chuck by about 70mm and use an ordinary drill.

 

[sparkdog]

That sounds a really good idea,good angle drills are so expensive.

 

[Richard]

Make sure you dont drill joists on the middle third of the span wont you ben......contravenes the building regs see..........

Between 25% and 40% of the span i'v always been told. Mind you ask a plumber and you'll probibly get something different again!

 

[sparkdog]

They don't seem to care,just hack out half the joist if its in the way.

 

[sjm]

Holes should be drilled on the centre line of the joist between 0.25 and 0.4 times the span of the joist and a maximum diameter of 0.25 times the depth of the joist.

As for the tool I've tried several right angle attachments and found the one from B&Q to be the best. I've now bought myself a 18 volt Li-ion Milwaukee impact driver and stubby wood beavers this works very well inbetween the joists, total length 270mm.

 

[brucelee]

and 3x the diameter of the hole apart before you drill another hole not side by side to create one huge hole lol