MF ceiling grid - hanger distance from walls

[Thorfun]

2 hours ago, crispy_wafer said:

can recommend the the blue bosch expert drill bits, brilliant! saves having to climb up and down ladders to fetch or carry 2 drills, especially when metal and masonry is involved.

Nice. They don’t do a 4.8mm bit though. 
 

although what’s confusing the Tek screws I have are DeWalt and say they need a 4.8mm bit but DeWalt don’t make a 4.8mm masonry drill bit that I can find. 

[joe90]

SDS ?

https://www.fixfast.com/sds-4-8#length=6891

[saveasteading]

Are you sure it is an sds bit?

They rattle about, deliberately, as a cross between drill and breaker and I'm not sure they drill precisely enough for this purpose.

The screw has to cut itself into the concrete.

Might be wrong.

[joe90]

3 minutes ago, saveasteading said:

Are you sure it is an sds bit?

I am not sure the OP is using an SDS drill but the one stove is SDS. I have used SDS drills fir concrete screws to good effect in the past (but at 8mm for mine).

 

your as bad as me, 11.30pm Christmas Day 🤷‍♂️ what are we like.

[Thorfun]

9 hours ago, joe90 said:

SDS ?

https://www.fixfast.com/sds-4-8#length=6891

Yeah I saw that. It’s not that I can’t find a 4.8mm bit I just think it’s weird that DeWalt make Tek screws that require a drill bit they don’t produce! 

[crispy_wafer]

If you are fixing into blocks you won’t need hammer on the drill, I’d be tempted to just try an hss bit somewhere, or just get an sds bit and stick that in the Chuck of your normal drill, an sds machine might just be a bit brutal.

Edited Thursday at 09:17 by crispy_wafer

[dpmiller]

I'd opine that a masonry bit won't drill accurately enough that you'll see a difference between 4.8 and 5mm.

 

And certainly with the blocks we get round here, you *will* need hammer...

[Thorfun]

32 minutes ago, dpmiller said:

I'd opine that a masonry bit won't drill accurately enough that you'll see a difference between 4.8 and 5mm.

 

And certainly with the blocks we get round here, you *will* need hammer...

I'm planning on asking DeWalt technical support what drill bit they recommend. I can't believe they'd recommend something they don't make themselves!

[joe90]

@Thorfun your over thinking this, DeWalt don’t know what substrate your drilling into and as said above different materials re act in different ways,

is your drill SDS?

Is it blocks or poured concrete your drilling into.?

there is a view above that SDS does not drill accurate holes (that I have not exieriehced)

so buy a 5.5,, drill and try it, if too tight then get a 6mm (or buy both fir the few quid they cost 🤷‍♂️)

[Thorfun]

15 minutes ago, joe90 said:

@Thorfun your over thinking this, DeWalt don’t know what substrate your drilling into and as said above different materials re act in different ways,

is your drill SDS?

Is it blocks or poured concrete your drilling into.?

there is a view above that SDS does not drill accurate holes (that I have not exieriehced)

so buy a 5.5,, drill and try it, if too tight then get a 6mm (or buy both fir the few quid they cost 🤷‍♂️)

overthinking is what I do best! 🤣

 

I'm fixing in to concrete blocks that form a block and beam ceiling. I have an SDS drill but also a standard chuck hammer drill too so either is possible.

 

I think 5.5 is too big. I have loads of spare blocks I can test on and can start with 5mm and see where that takes me.

 

I know DeWalt might not know but I'm really confused as to why they say a 4.8mm bit when they don't offer one. it's not like DeWalt at all! normally a manufacturer will only recommend their own products so they can sell more stuff. and yes I am a cynical b*****d.

Edited Thursday at 11:18 by Thorfun

[joe90]

26 minutes ago, Thorfun said:

think 5.5 is too big.

Sorry I meant 4.8 (git confused with my own comment on red rawlplugs !!!). Great idea to do tests and what works best for what you have. 👍 personally I hate normal hammer drills, SDS does such a better job IMO.

[Thorfun]

first experiment underway. 5mm SDS bill. it seems pretty darn solid but will see how long it lasts.

 

[joe90]

34 minutes ago, Thorfun said:

first experiment underway.

Brilliant, how tight did the screw feel putting it In?

[Thorfun]

Just now, joe90 said:

Brilliant, how tight did the screw feel putting it In?

yeah. pretty tight. I'm sure it'll be fine and the final load on each screw for the ceiling won't be as much as a concrete block pulling straight down as the load is spread across the whole ceiling and all the screws.

 

so maybe for the sake of a few screws I reduce it to a 600mm x 600mm grid and that will then be completely over the top for fixings and reduce the load per fixing as well.

[Nick Laslett]

1 hour ago, Thorfun said:

first experiment underway. 5mm SDS bill. it seems pretty darn solid but will see how long it lasts.

 

This tread has been some of the best alternative Christmas entertainment. Needs a good cliff hanger for New Year’s Eve. 

Edited Friday at 12:56 by Nick Laslett

[Pocster]

18 minutes ago, Nick Laslett said:

This tread has been some of the best alternative Christmas entertainment. Needs a good cliff hanger for New Year’s Eve. 

A smashed ceiling on the floor perhaps ? 

[saveasteading]

13 minutes ago, Nick Laslett said:

Needs a good cliff hanger for New Year’s Eve. 

With a soppy sentimental story on the side.    

My great Aunt Gertrude rescued me from the slums. Her greatest wish was that some day I would fix a ceiling grid using self tapping screws into concrete. This is in her memory. 

But will I manage it?.

Music "Dih dih daaaah! 

 

Fortunately a helpful group of blog members hear of this and offer advice.

 

 

 

[Thorfun]

so experiment number 1 is a success as far as i can tell. it's not budged a mm and has been hanging with that weight for 72hrs. so i think i will be fine using the 5mm SDS bit.

 

But, because i'm not a cowboy like @Pocster, i have ordered a 4.8mm bit anyway.

 

will be interesting to see if i can "feel" any difference when fixing the screw.

[Pocster]

3 hours ago, Thorfun said:

But, because i'm not a cowboy like @Pocster, i have ordered a 4.8mm bit anyway.

Yeah yeah . Don’t forget the photo of your ceiling ….. on the floor 😊