Filling a hole in Wimpy no Fines wall to redrill

[SVRich650]

Hi

I was hoping someone would know how to help. My house is wimpy no fines (https://www.bisfhouse.com/wimpey-no-fines-in-situ-concrete-house/) so the external walls are loads of decent-sized pebbles and gaps. This means drilling into them is a pain in the arse and something I haven't tried much especially of anything heavy to be attached to the wall..

I am trying to mount a TV on a wall and as usual, drilling made a mess of the wall and didn't really split any of the pebbles so I used a small chisel to make a bigger hole with the intention of filling it and then drilling a clean hole (obviously I will do more holes for the other mount points), I just wondered what the best filler would be so I can mount about 10/11kg of TV and bracket. The hole is about the size of 50p



Ta

Rich

 

[JP_]

How deep is it? Maybe polyfilla? But maybe don't take my advice ...

 

[SVRich650]

It's about 5cm deep.

 

[JohnD]

sand and cement. Wet the hole first, and poke it in with a pencil so it is dense with no air pockets. You can press your plasplug into it while it is wet, so no need to drill again.

Mist the wall frequently for a day or so to keep the cement wet while it cures.
Press it slightly below the level of the plaster so that when you tire of it and want to fill the hole, there is no need to pull it out and leave a huge crater.

A hole the size of 50p is ludicrous. If your hammer drill with a masonry bit won't make a hole about 8-10mm dia, you probably need to invest in an SDS+ drill. Ask your neighbours what they do. I have never had a no-fine house so this is not from experience. If your whole house is like that you need a suitable tool. You can buy a poor-quality one (very heavy) for about £60 with a starter set of steels. Good ones are quite a lot more. Wait until you have a significant job to do, because although the cheap ones are poor quality, they usually have a 2-year guarantee, so you have a good chance it will last long enough to do the work, and you will get your money's worth. They are strong and brutal, as usually used for reinforced concrete.

 

[SVRich650]

sand and cement. Wet the hole first, and poke it in with a pencil so it is dense with no air pockets. You can press your plasplug into it while it is wet, so no need to drill again.

Mist the wall frequently for a day or so to keep the cement wet while it cures.
Press it slightly below the level of the plaster so that when you tire of it and want to fill the hole, there is no need to pull it out and leave a huge crater.

A hole the size of 50p is ludicrous. If your hammer drill with a masonry bit won't make a hole about 8-10mm dia, you probably need to invest in an SDS+ drill. Ask your neighbours what they do. I have never had a no-fine house so this is not from experience. If your whole house is like that you need a suitable tool. You can buy a poor-quality one (very heavy) for about £60 with a starter set of steels. Good ones are quite a lot more. Wait until you have a significant job to do, because although the cheap ones are poor quality, they usually have a 2-year guarantee, so you have a good chance it will last long enough to do the work, and you will get your money's worth. They are strong and brutal, as usually used for reinforced concrete.

The hole is that big because I used a chisel as my hammer drill and masonry bit barely got past the plaster.

As you have probably guessed I am not all that good at DIY and I've never mixed cement before so I don't know what ratio would be best or would it not matter too much?

 

[JohnD]

5 of sand to 1 of cement will do (it's quite a weak mix)

mix it up in an ice-cream container

less water than you think

If you put water in first, them add cement, it will minimise dust while you work. Preferably mix it outdoors because of cement dust.

I find it's also very good for bedding in electrical back boxes and the first layer of chases (stays workable longer than plaster).

Wet the hole first and mist the job once in. Cement hardens by chemical reaction with water so must not dry out or it will stop hardening (and will not restart). A day is the shortest time to get any strength.

Don't rip the bag open like this idiot. Cut it neatly across the top so you can fold it tightly to keep air out. You can mix it with an old knife. If the mix looks black or dark grey it probably has too much cement. You can buy small amounts in strong plastic bags.

 

[foxhole]

Strange approach , do you have sds drill ?, anything else is pointless.

 

[SVRich650]

Strange approach , do you have sds drill ?, anything else is pointless.

I am strange, I don't have and sds drill no. I must admit I didn't really realise what the difference was.

 

[foxhole]

I am strange, I don't have and sds drill no. I must admit I didn't really realise what the difference was.

You will always struggle without correct tool for the job.

 

[SVRich650]

Would this be any good?

https://www.screwfix.com/p/titan-ttb653sds-5-9kg-electric-sds-plus-drill-230-240v/6846h

As I assume this would be too lightweight:

https://www.screwfix.com/p/energer-enb569drl-2-6kg-electric-sds-plus-drill-230-240v/15456

 

[JohnD]

yes, that's one of the "poor quality" cheap, heavy ones I had in mind. The one with a starter set of accessories is
https://www.screwfix.com/p/titan-tt...us-drill-9-piece-accessory-kit-230-240v/97533

If you keep an eye on them you will see special offers, especially just before a bank-holiday weekend or an end-of-month payday.

Observe the long guarantee. I got one for a heavy job and it still works.

You sometimes see other cheap tools in lidl and aldi. The Lidl ones come from a major german maker and some spares can be ordered online from Germany. I don't know a source for Aldi, but if you get a fauilty one and take it back I believe they are good on refund and exchanges, so if you have a major job coming up and the store is near you, worth a punt.

For all I know they're all made in the same Chinese factory.

 

[SVRich650]

I was reading this thread that was saying the big heavy powerful drills are overkill and can actually make a job more difficult so now I am wondering if this one would be more suitable:

https://www.screwfix.com/p/mac-allister-msrh600-2-6kg-electric-sds-plus-drill-220-240v/994fy

It's less powerful but much lighter. I could do with adding a handrail to another external wall as my mum has issues climbing our stairs when she visits, as that would need quite a few more holes would the heavy one be a problem..

 

[JohnD]

It does look a lot lighter and handier.

 

[SFK]

SVR,
I have used both the drills yo posted links to in your earlier post.
They are both good (although poor quality).

The issue I have with the 'big one' is that I could not lift it long enough to use, especially when say fitting Curtain Rails. This causes issues as the drill can droop when drilling making hole bigger. I also look a fool when carting it around. But it is good for breaking up concrete around bottom of fence posts
https://www.screwfix.com/p/titan-ttb653sds-5-9kg-electric-sds-plus-drill-230-240v/6846h

So for normal use I like using the small one you have a link to, BUT this is Screw fix being annoying as that drill does not exist anywhere for £9.99 otherwise I would have bought another (perhaps there is ONE somewhere, but Screwfix seem to do this annoying tactic lot).
https://www.screwfix.com/p/energer-enb569drl-2-6kg-electric-sds-plus-drill-230-240v/15456

Note that the Key number for SDS drills is the Impact Energy. Big one above is 8.0J, smaller one is 2.5J.

In your new post the drill you have just suggested has 1.6J.
If it was my money today I would say that that 1.6J might not be enough for your walls and future use.
But I feel you need a lighter drill or you will never use it.

So at Screwfix I would currently get the £50 one you suggested with 1.6J or the following at £70 with 3.0J of Impact Energy (note that as this is a 'cheap' brand I bet they are overstating their 3.0J of Impact energy over the Brandnames). :
https://www.screwfix.com/p/erbauer-erh750-3-4kg-electric-sds-plus-drill-220-240v/232fv

SFK

 

[foxhole]

I prefer dewalt.
https://www.powertoolworld.co.uk/de...Yt8jyCAvQhHV1AdReXp61tGSrRNSjLXxoCwLYQAvD_BwE