Info Needed About Screwing Please............

[Fourby]

Hi folks
Now that the plumbing, re-wiring, plastering, is finished, I'm about to fit our new kitchen. It's only small, but at £1500 to have it fitted, I'm more than confident at fitting it myself. I know that most if not all the fixing's that come with it are pretty basic and naff so what I'm asking is, when I put up and fix the top cupboards to the wall, I only have the thickness of 1 breeze block to drill and screw into, can anyone recommend a GOOD plug and screw for fixing into breeze block ???

Thankyou............. Fourby

 

[fitter]

I have tryed proper breeze block fixings but did not find them that great ( could have been using them incorrectly), I always use 2inX10 pozidrives in a good fitting red plug, so far so good ( that's the kiss of death).

 

[AdamW]

I bought some heavy duty grey nylon plugs in Wickes that expand in all 4 ways. They are holding things on a treat in my bathroom.

Normally I use heavy duty brown plugs with a pozidrive for heavy things.

 

[david and julie]

The internal wallls of my house are of blocks which I believe are made of fly-ash or similar waste material. It is a total waste of time trying to fix anything to them. When fitting anything really heavy.I always drill holes about 3/4 inch in diameter (a flat wood bit does it!)then ram them full off heavy duty fast-set filler. After it as set you will be able to use the fixings supplied Its a bit long winded but I've never had one fail.

Chemical fixings are available at hilti, probably very expensive though!

Good Luck, Dave

 

[David P]

chemical fixings are fairly easy to get hold of or even to make yourself using catalysed filler such as plastic padding or chemical metal - some even use gripfill - but they are not really needed for thermalite block, it would be overkill.

the secret of making good fixings is accuracy - drill a hole that is exactly the right size for the plug (it should need to be gently tapped in with a hammer) - the hole should be deep enough to take the whole plug, and of course what remains of the screw once it has gone through the thing to be fixed. the screw should screw in until the wall is reached and then get tighter. if it keeps turning it is a bad fixing, take it out and add some extra material (slivers of wood, sandpaper, etc) into the hole and try again.

remember fixings on vertical surfaces are mainly anchors against a vertical force - that is, the weight is trying to shear them rather than pull them out. strangely enough in shear the depth of the fixing is immaterial after about the first half inch - so adding longer fixings simply strengthens your confidence.
having said that - when a object has upper and lower fixings i.e. the fixings of a cupboard. the top ones will have some tension on them (force pulling it out of the wall) due to the cupboards tendency to want to rotate around any lower fixings. but this is still only a small proportion of the 'weight' of the cupboard as most of all it just wants to go downwards, moving outwards first will usually take some external assistance - such as a person pulling on a stiff door.

all in all putting fixings in soft material is an easy task - at least there is no hardspot to force the hole oval or air pockets to dissapear into.

 

[AdamW]

the depth of the fixing is immaterial after about the first half inch

Don't think I will be testing this theory!

Shear isn't the only force applied to a fixing. It is, as you say, the major force however this is only when the fixing is long compared to its diameter (i.e. more than half an inch long!). There is also a moment around the point where the fixing meets the surface of the wall. So, the longer you make this fixing the greater the reaction the wall can apply back to the fixing and thus the screw (think of the screw as a lever with one end at the screw head, the fulcrum at the wall surface and the wall applying a force at the other end).

Also the longitudinal force along the fixing is greater if the fixing is longer as there is a larger contact area between the fixing and the wall. Thus you are less likely to get problems from people pulling on stiff doors, as you say.

So, to sum up, the heavier the load you hang from the fixing, the longer you need the fixing. A block wall will NOT take a heavy mass hanging off a half inch fixing, it will crumble!

 

[AdamW]

Just remembered something else: a fixing is stronger if you tap it THROUGH the plaster so the whole fixing is sitting in the wall material. For this you can use dowel (wood or metal): just large enough to cover the fixing. You can use a large screw or bolt turned back to front (so the head is pushing the plug) but bare in mind that you can get nasty metal chips flying off the hammerhead if you do that.

If you use the latter method, wear safety specs!

 

[Scoby_Beasley]

If you use the latter method, wear safety specs!

Overkill maybe, but I would always advise anyone to wear safety specs when doing jobs like this, mind I do wedding photos on a weekend and work in engineering with metal splinters flying about the rest of the week so I know you may have 20 wall plugs , 4 drills, 200 screws but only 2 eyes, look after them (says the man who got splashed with caustic soda in the face today !! )

 

[Scoby_Beasley]

Just remembered something else: a fixing is stronger if you tap it THROUGH the plaster so the whole fixing is sitting in the wall material. For this you can use dowel (wood or metal): just large enough to cover the fixing. You can use a large screw or bolt turned back to front (so the head is pushing the plug) but bare in mind that you can get nasty metal chips flying off the hammerhead if you do that.

If you use the latter method, wear safety specs!

Agree with this also, set your drill on 'normal' to get through the plaster then 'hammer' into the brick and tap your plug into the brick fully, adjust the length of screw to suit your (never level) plaster thickness

 

[masona]

Fischer screw do large range of difference type of fixing, I don't use anything else.

 

[AdamW]

Overkill maybe

You could be right, I have never had metal chips fly off from striking a pointy thing with a hard thing, but the warning labels are on every hammer I own!

I invested in a good respirator, goggles, riggers gloves and ear-defenders for my last big project. Now I can't hammer without the ear defenders! I was glad of the goggles when chipping bathroom tiles off, had several chips fly right towards my eyes. Phew!

I have been watching a series called "American Hotrod" on some satellite channel and these hotrod builders are grinding metal, arc welding, beating all without any protective eye wear, ear defenders, respirators or goggles. Seems a bit foolhardy... Bl**dy nice cars though!

 

[Fourby]

Thank's for all your info and advice guy's

 

[joseph77]

Hello Adam,

ive been watching hod rod to - great program all most as good as american chopper!!! Also out of interest how do you guys fix any thing to a wall in a new house with breeze blocks like butter and then dot and dab plaster with the air gap inbetween, im glad i live in a "properly built" older house.

joseph