Using A Core Drill

[dlm2310]

Need to hire a core drill for bathroom to fit an extractor fan.

Are these simple to operate for someone who has not done it before ie me ?

I did have a sparky booked in to drill and fit fan for £120 but he has let me down and I am having trouble finding another who has a drill.

Would I be best hiring one myself for £40 or getting a plumber maybe to come out (I assume most plumbers have core drills ?) I don't really want to **** it up as the wife wouldn't forgive me !!

Cheers

 

[^woody^]

If you have a drill, you could buy a tungsten carbided tipped core drill for about £25, which will do you for about 4 holes. If not you could buy a cheap sds for about £20 too.

Its not hard, you just need a slow speed and take it easy. You can do it of a secure ladder, but a platform is best. Try to keep the drill level.

Others will be along to mention the merits of a drill with a clutch. Personally, I would not be concerned if you take it steady, don't press and let the drill do the work

 

[dlm2310]

Thanks,

Yes I have a drill I will look into getting a bit.

I know this might sound daft but I assume I would drill from the inside out ? Assuming this would limit damage on bathroom wallpaper than if I went from Outside to in.

I assume if the hole is for a fan then I will need to drill it a slight downward gradient so any excess water in the ducting will flow out ?

 

[libby lou lou]

You was told, after asking, keep the drill straight, so, do that, woody, sds keeps appearing, what does it mean

 

[^woody^]

You could do, but I would drill the inside wall from the inside, and outside wall from the outside, then no damage to any face. There is a chance that the external brick may chip when the core exits, and the chip may be bigger than the cover you fit

You have to remove the bit half way anyway to remove the brick/block core from the bit

You should get neglible moisture in the duct, so a fall should not matter. In any case, you should drill the hole level and it should be slightly oversized to the duct, so you have room to angle the duct pipe if you want. I would not worry about it

But, the way the typical fan kits snap together, if you angle the plastic duct, then the fan and external cover may not sit square on the wall - as they fit tight in the duct with little play

 

[Richard C]

Before you go drilling holes through the wall, have you thought about going up through the ceiling & ducting out through the soffit board - much easier if you have a route!

You can use an ordinary masonry bit to drill around the outline & then knock out the centre with a hammer & chisel; it takes longer (but not much!) & if you’re careful you can achieve equally good results. Keep the hole square & drill a pilot hole through both walls first (assuming it’s cavity) & use this hole as a datum, that way you can drill each wall into the cavity to minimise visible damage; if you punch through the brickwork from the inside, great chunks will come off the brick face & it will look a complete mess.

 

[^woody^]

... sds keeps appearing, what does it mean

SDS drills work differently to basic hammer drills. They use a pnuematic mechanism to deliver stonger hammer blows, rather than just cogs in a normal hammer drill. I don't recall what sds actually means - some foreign words probably as it was invented by Bosch

They are the drills without a traditional chuck which you tighten by hand or chuck key, but rather the drill bits just slot in. They use special drill bits.

Bottom line is that they will go though the toughest material, whereas a normal hammer drill will just slide across the surface

 

[Richard C]

Sorry I seem to have repeated you woody, that's the trouble with editing off line!

SDS stands for Special Direct System (Bosch) & here is a useful link http://www.diyfaq.org.uk/powertools/sds.htm

 

[libby lou lou]

2310

My post seems so ignorant, was'nt meant to be that way,please accept my apologies.

thanks for that Richard.

 

[Richard C]

2310

My post seems so ignorant, was'nt meant to be that way,please accept my apologies.

Not at all; that's why the forum is here!

 

[^woody^]

A quick google gives

Slotted Drive Shaft,
Slotted drive system
Schnell Drilling System
Steken Drehen Sitzt (Insert Twist Lock)

I would think it is an acronym of some German words

 

[dlm2310]

Thanks everyone for their advice

 

[Richard C]

A quick google gives

Slotted Drive Shaft,
Slotted drive system
Schnell Drilling System
Steken Drehen Sitzt (Insert Twist Lock)

I would think it is an acronym of some German words

Here's the one I found; http://www.technologystudent.com/pwtol/drill4.htm
Looks like take your pick!

 

[AndersonC]

My electrician drilled a pilot hole, from the inside of the bathroom, through both inner and outer walls with a standard SDS masonry bit. He then drilled in from the outside with the core drill, with the core drill bit centred on the original pilot hole.

Drilling in from the outside allows you to patch up the inside wall relatively easily with plaster/filler and then decorate over it. Patching up external bricks couldbe more tricky, especially if you want the outside walls to look tidy.

WRT drilling both the inner and outer towards the cavity, you'd have to be careful to prevent large pieces of debris falling into the cavity which could then give future problems with penetrating damp.

 

[dlm2310]

Thanks, I have got cavity wall insulation so no danger of anything falling into the cavity.

Was asking about drilling inside out just because my bathroom is decorated and don't feel like redoing it at the moment !!