what bit and drill to use

Shaunoc

i'm looking to drill a 22mm / 25mm through cavity wall to let an expansion pipe of 21.5mm through. (150mm block - 150mm insulation - 150mm block + 50mm ish allowance render)

I have an SDS hitachi drill
Is there such a bit available at non crazy money or is there a clever way to do this? Like a pilot hole with a skinny bit first...?
Would like to do a neat hole and try not to ruin the napped plaster on the gable.
Would the drill i have be capable or is something more powerful needed?
It is for a one off diy job.

Thank you diyers

5T3PH3N

If your drill is corded sds it should be able to drill up to 24mm holes I think, look up the model number on your drill and see what it's rated for.

You can get 24mm bits in 550mm/600mm lengths, most shops will probably charge 30€ plus for that size but I'd say you could find it online for a lot cheaper.

Your local tool hire shop might give one to you for feck all if you get it back to them in an hour or 2.

Is it full fill insulation cavity? There might be a cavity there so you may need a longer bit.
Usually we drill into the building to prevent render blowout and usually a pipe entry will be covered inside so any light damage that may occur to the internal plaster doesn't matter.

Shaunoc

Yes, corded sds.
There is full fill insulation.
I will have to drill from inside to out which is why i'm a little concerned about busting the render.
Maybe a silly Q - would an sds plus bit, fit to an sds drill chuck or is an adaptor needed?

5T3PH3N

Shaunoc wrote: »

Yes, corded sds.
There is full fill insulation.
I will have to drill from inside to out which is why i'm a little concerned about busting the render.
Maybe a silly Q - would an sds plus bit, fit to an sds drill chuck or is an adaptor needed?

Yeah, sds plus is standard sds bit, sds max is for the bigger drills/breakers.
If you have to drill out then maybe get an 8mm bit and drill out with that first, just let the bit do the work and don't lean hard on it, then use your 24mm bit nice and easy. Drill down at a very slight angle. You're never sure that the render will stay intact no matter what way you drill, sometimes switching the drill from hammer drill mode to rotary mode for the last bit of the hole will help prevent blowout.

mickdw

5T3PH3N wrote: »

Yeah, sds plus is standard sds bit, sds max is for the bigger drills/breakers.
If you have to drill out then maybe get an 8mm bit and drill out with that first, just let the bit do the work and don't lean hard on it, then use your 24mm bit nice and easy. Drill down at a very slight angle. You're never sure that the render will stay intact no matter what way you drill, sometimes switching the drill from hammer drill mode to rotary mode for the last bit of the hole will help prevent blowout.

You hardly have 2 layers of 150mm block?

Anyway, id drill it out with an 8mm, follow with the full size then drill the last portion from outside inward to safe the plaster finish.

5T3PH3N

mickdw wrote: »

You hardly have 2 layers of 150mm block?

Anyway, id drill it out with an 8mm, follow with the full size then drill the last portion from outside inward to safe the plaster finish.

Yeah I've never seen 2 leafs of 6 inch block but it's not impossible.
Op said he'd be drilling from inside, I assume he cannot drill in.

Shaunoc

You're right lads. Its 100mm block. New baby sleep deprivation!
I cannot go inwards.
I'll go with your suggestion of 8 followed by 24 in the new year after sleep

the_pen_turner

I would buy a long (400-500mm) 8mm drill bit . it is handy for wires etc and hire the 24mm bit. I have an sds max one that I bought 2 years ago for a job but didn't need it in the end, still havnt used it, I will eventually but most people would never need it again

my3cents

Shouldn't the OP be drilling a much bigger hole for a larger pipe to line the hole before inserting the expansion pipe?

Shaunoc

Line with and why?

the_pen_turner

Shaunoc wrote: »

Line with and why?

It's good practice to put any pipe or wire inside a larger pipe. It helps protect the pipe or wire.

Mikewalsh

the_pen_turner wrote: »

It's good practice to put any pipe or wire inside a larger pipe. It helps protect the pipe or wire.

Isn't it a regulation, I remember a plumber saying it was a rule?

Is there plumbing regulations?

DublinDilbert

the_pen_turner wrote: »

It's good practice to put any pipe or wire inside a larger pipe. It helps protect the pipe or wire.

It means you can foam/cement the outer sleeve pipe in place, then run your cables/wires or pipes inside this.

my3cents

DublinDilbert wrote: »

It means you can foam/cement the outer sleeve pipe in place, then run your cables/wires or pipes inside this.

Also means you don't damage your new expansion pipe when you push it through the liner and if it does for some reason get damaged you don't end up with a cavity full of water.

But I think the main point is its to seal the cavity.

the_pen_turner

Mikewalsh wrote: »

Isn't it a regulation, I remember a plumber saying it was a rule?

Is there plumbing regulations?

I'm not up on plumbing regs.

Shaunoc

In simple terms... (Correct me) I need to drill hole wide enough for an inch pipe and then slip the 22mm through it? I will not need a duct for other pipes\wires. To seal gaps, silicone sufficient? Plus some probable plasterwork patching.