Attaching Wood to Brick - gone wrong

Discussion in 'Carpenters' Talk' started by gettingbetter, Jul 6, 2011.

  1. gettingbetter

    gettingbetter New Member


    This is a bit of a long post, but I wanted to highlight my problem clearly to facilitate accurate replies.  Thanks in advance for any advice you may be able to give.  The actual questions are in <strong style="color: #ff0000; ">red[/b] at the bottom for ease of reference. 

    I am trying to attach a long vertical wooden batten to brickwork, from floor to ceiling.  It will be used to hold up a reasonably heavy large plywood door on some built-in alcove shelving.  It is shown in the picture below.
    I am using these frame fixings to attach it to the wall:

    As per the instructions on the box, I drilled 8mm holes in the batten (see picture below) and pressed the plugs through the holes:
    I then drilled 8mm holes in the brickwork, thoroughly vacuumed the holes, and attached the batten to the wall using the plugs that I?d pressed through the batten beforehand.  I am now trying to screw the supplied screws (4mm x 125mm, see image below) into the plugs to secure them and only a couple of them will go all the way in.
    Most of them go ¾ of the way in and then jam.  When I try to force them, the drill shears the pozidriv markings on the screw (I have gone through dozens of screws from this pack in that manner) rendering them useless.  I just can?t get the torque to turn them all the way in.
    I know the holes are straight, because I?ve tried just sticking the metal screws into them without the plugs and they all fit fine.  I tried using a B&Q screw I had lying around and it went in fine too, so it really is the softness of these Rawl Plug screws that is the problem ? they just disintegrate under stress from the screwdriver.  I therefore need to get replacement screws that are tougher and able to handle the torque required to get them all the way in.  I called Screwfix (from whom I bought these frame fixings) and they were unable to advise me on whether or not they had screws matching the size I need ? they said the Rawl Plug screws are unique and hence couldn?t be replaced directly by a standard screw.   I can?t believe how easily the Rawl Plug screw heads get worn away.  I was previously using some frame fixings from B&Q for the shelf-support battens (see below) and had no such problems.  I switched to the Rawl Plug ones at Screwfix because they were vastly cheaper.  I thought they?d be good quality being a brand name.{9372015}/categories%3C{9372044}/categories%3C{9372210}/specificationsProductType=frame_fixings

    So anyway, I?ve been looking online for 4mm thick x 125mm long screws (or even 4mm x 115-120mm) and have had no luck.  I?ve looked at popular kinds like Turbo Gold and Spax etc and haven?t been able to find the size I need.  All screws of that length seem to be thicker than 4mm.  I can?t even find 5mm thick in that size.  I tried using a 6mm thick screw and it tore the plug.  I can?t use less than 120mm in terms of length, because it doesn?t fully expand the plug.  From left to right, the image below shoes the result of a screw that is too short (4mm x 100mm), the correct supplied screw (4mm x 125mm), and a screw that is too thick (6mm).
    So, I need one in the original 4mm x 125mm measurement AND with a tougher head that doesn?t get sheared.  I was thinking that a Torx or Robertson (Square) or Hex slot might work better (see below) after reading up a bit on torque etc.

    E.g. the following two links show Hex heads which look like they?d handle more torque than the Pozidrivs but are too thick

    <strong style="color: #ff0000; ">Please can anyone advise me on where to buy the 4mm x 125mm screws with a tougher Pozidriv or Hex/Robertson/Torx head?  If I can't find those screws, my only other options would be the following two:[/b]

    <table border="1" cellpadding="3" cellspacing="0" class="jiveBorder" style="width: 100%; border-top-color: rgb(0, 0, 0); border-right-color: rgb(0, 0, 0); border-bottom-color: rgb(0, 0, 0); border-left-color: rgb(0, 0, 0); border-top-style: solid; border-right-style: solid; border-bottom-style: solid; border-left-style: solid; border-top-width: 1px; border-right-width: 1px; border-bottom-width: 1px; border-left-width: 1px; "><tbody><tr><th align="center" style="background-color:#6690BC;" valign="middle">
    <strong style="color: #ff0000; ">Can anyone advise on which of the two would be the better option?  Can the frame screws actually grip into brick properly without plugs?[/b]

    I know this is a long post.  Thanks for reading to the end.  Any advice you can offer would be massively appreciated.

  2. a1colly

    a1colly New Member

    Just a quick sugestion, why not try uprating to the following

    change the plugs for some of these 10mm babies

    and then countersing some of these coach bolts which youll have no problem driving in

    A little over kill for what your doing but your garanteed for strength and you can drive it in with a good old socket if the going gets tough.
  3. jeznotts

    jeznotts Member

    crikey dude you are making a meal of this! where do i start? well i think that the fixings are just too long 125mm is really long for a 50mm batten (not spec'd but looks like)  into brick i would probably use something like an 80x5mm screw with a brown plug (7mm) the reason that you are stripping the heads could be that the hole isn't deep enough or you have the wrong driver, rawlplug stuff is the same as most and should be ok for what you are doing!
    so start again get some shorter screws, brown plugs drill the depth of the drill bit( assuming you have a standard length) as you have to allow for the plug,dust,ect tap the plug through  the wood where you have drilled this way your plug will line up with the hole, tap in the screw until you feel resistance then screw it in!
  4. joiner1959

    joiner1959 Active Member

    Hi, in the time its taken me to read this post I could have finished your framing
    You could go with the screw and plug set up as jeznotts says or why not try hammer fixings(100mm) Bore the appropriate size hole in the timber,hold in place and mark position of hole in brick (if you have a good bit and a powerful enough gun bore through both at once) Bore to correct depth plus a few mm clearance using a bit of tape on the bit as a guide or use a depth stop if you have one. Put timber back in place and insert fixing and hammer home. Dont remove the screw headed metal insert from the plug,hammer them both in together.
    Job done.
    Hope this helps.
  5. Mr. Handyandy

    Mr. Handyandy Screwfix Select

    Or use an 8.5mm drill bit.

    You have to allow for the hardness of what you are fixing into. If there is no room to expand(hard brick) you should allow an extra half to one millimetre for expansion.

    In soft brick/block/mortar a tight hole works.

    A tip. Dip the point of the screw into some fresh silicone before fitting. This will lubricate it, making it slide in easier(and will dry up later).

    Mr. HandyAndy - Really
  6. jeznotts

    jeznotts Member

    pressed reply earlier without finishing! good point john they also work however i always find that if i take the screw out and then put the plug in it takes better! personal pref i guess! i think that you are over complicating one of the most basic and most practised processes in carpentry, perhaps one of the diy youtube clips will give you a visual reference to what we are saying! good luck!, getting better:)
  7. Pink Panther

    Pink Panther Member

    Gettingbetter, it may be some consolation to know that you have won the 'Best Orignal Opening Post of the Year' award. Well done. Have a Boopy.

    Mind you, you are absolutely right about these fixings - they are stupidly soft. I have had exactly the same problem as you and will never use them again as a result. I don't understand the 'reasoning' behind the use of such soft metal - standard wood screws are hardened steel and are miles tougher. And are cheap. So why use a butter-soft metal for these, I dunno.

    So, unless you can find decent 5-6" screws of that narrow thickness to replace them with, then go for one of the suggestions given in the posts above. And never buy these awful fixings again. It's nothing you've done wrong - they are just rubbish.
  8. jeznotts

    jeznotts Member

    been quiet lately handy? the bricks are not very hard in this case, as in most and at the end of the day 7mm plugs require a 7mm hole 10mm plugs require a 10 mm hole and so on regardless of the hardness of the material, its the screw that on some occasions you have to change (rarely though) as for the silicone, well never seen that before either but whatever floats yer boat! ;)
  9. jeznotts

    jeznotts Member

    wow are they really that bad? haven't used them for years, take em back and get yer money!
  10. Mr. Handyandy

    Mr. Handyandy Screwfix Select

    Look, Jezsnotts, you are doing it again.

    You are dismiss my advice when it is so obviously more advanced than yours.

    You started in this thread by saying that you would use 80mm screws for 50mm batten(2" lump of wood).

    So you would have 30mm of screw into the wall ? That's not even enough to fill a normal rawlplug!

    What are you on ?

    Then you say these bricks are not hard. Excuse me ?

    You cannot possibly know this, and to MY eye, those bricks could possibly be quite hard.

    LOOK at how a wall plug works. It needs to expand.

    It is the whole principle behing plugs. They expand when a screw is inserted ALL THE WAY, not just 30mm into.

    If a wallplug is too tight, and cannot expand at all, the screw will just EAT the plastic, and render the plug almost useless.

    Don't bother arguing. Your advice is crass.

    I am right.  You are not. Don't bother arguing. You fail!

    30mm to hold 50mm!!!! Pffffft.

    Mr. HandyAndy - Really
  11. jeznotts

    jeznotts Member

    yeah well if you were to leave the the screw head flush with the batten then it would be only 30mm but of course we never do, it nomally sinks in 10-15mm perhaps further also i said something like. perhaps with you i have to be more specific ( will be in future) your advice isnt more advanced as its wrong, where has it ever been stated that you use a bigger drill bit than the size of the plug???(except in handyworld) also having worked with bricks my whole working life, oh and concrete, granite ect i can plainly see that they are standard bricks( engineering bricks are the hard ones and dont look like that and anyways they are not so hard that they pose any type of problem!))  needing a 7mm drill for 7mm plug ect (yawn) the only way a plug will be too tight is if you use the wrong size drill bit! also yes the plug expands but guess what the people who make the plugs have thought of this so allow this in their manufacture! other wise they would state that you could use any size as long as its around the size we specify, i reckon!  im not arguing with you, just ammusing my self as i have forgotten more than you know about this trade! we can all tell as you get you back up,just a bit, when people challenge you on your advice! NEXT, really!
  12. Cityboy

    Cityboy New Member

  13. Mr. Handyandy

    Mr. Handyandy Screwfix Select

    It's no good trying to back-pedal jesnot, a screw is best when dead flush with the surface, and well you know it (or should, if you are supposed to know so much).

    What happens when a plug cannot expand at all, is that the screw either chews it up, or self-tapps into the plastic, NOT expanding, and NOT becoming tight.

    Take a look at how the damn things work before spouting sh|te.

    30mm to hold 50mm of wood!!!!! Pffffttt!

    Now that IS laughable.

    Take a look at some of those bricks. Some look like a harder type.

    Mr. HandyAndy - Really
  14. jeznotts

    jeznotts Member

    ooooo! (holds up handbag) ok whats the difference between flush and sunk in? there is still the same amount of wood being held by the screw head! if you encounter a situation where the plug wont expand (happens a bit here and then) it quite obvious so you go with drilling it out and trying again or moving the fixing! (this is normally coz the material fails or the hole is too big)
    also i think that your whole point to this was because you think that the hardness of the material has an effect on wether it will expand or not, well not true as i explained to you there is a tollerance built into the fixing to allow expansion ,take a look at how the damm thing works before spouting ****, and i can see that you will keep on about the 80mm thing (wouldn't be 30mm more like 45mm) well tell ya what mandy ill say just for you that ok lets change that to a 100mmm fixing! had another look at the bricks and 'whatever'!
  15. jeznotts

    jeznotts Member

    sorry cityboy i just can't help it seeing him write his stuff out here in tradesmans world, too funny! don't think that i will need to mention the floorboard thing as he seems to have clammed up about that! , i meant to ask him if he thought the 'wobbly' bit on the end of his tape meant it was broken!
  16. Mr. Handyandy

    Mr. Handyandy Screwfix Select

    You idiot jesnott.

    If you allow the screw to pull through 15 odd mm, you will only be holding 30-35mm of wood.

    The strength in a screw is when the head is countersunk(self or otherwise) to be flush. That way, you are holding the full 50mm of wood.

    As I said YOU KNOW that. You are just back-pedalling to save your face.

    It ain't working. You are showing yourself up.

    30mm in the wall!!!! Pffffft!  Sink it in the wood 15mm ???????????? Double pffffffttt!

    What an idiot.

    Let's see the OP sink a screw into his 7mm hole and 15mm into the wood!

    Idiot Jexnsot.

    Mr. HandyAndy - Really
  17. joinerjohn1

    joinerjohn1 Screwfix Select

    To the OP. You obviously haven't drilled the holes in the brickwork deep enogh to accomodate the screw. The screws you were using are 125mm long and the timber is 50mm thickm therefore you have to drill into the brick at least 80mm. You'd have been better off using 100mm length screws and drilling around 60mm into the brickwork.
    FAO Handy, Whenever I've put up stud work etc , modern quick grown timber is that soft, I can easily get a screw to pull in 10mm or so into the timber. Even when screwing the top and bottom of the studwork partition to the studs (and thats screwing into end grain)
  18. jeznotts

    jeznotts Member

    ta joiner john i metioned also that the frame fixings were too long! i know for a fact that 80s would hold too as long as the screw grabs the plug properly i use that size to fix stud frames together too, if im not nailing them!
  19. jeznotts

    jeznotts Member

    bet you didn't  think it would go on this long!
  20. Pink Panther

    Pink Panther Member

    Jeezus Kuryssst, boys, give it a rest.

    Give the onlookers on this forum enough credit to know who's talking barlocks and who isn't*. So we DON'T need this painful point-scoring. It's clear that neither of you are particularly bothered about facts as such, just getting one over the other. Which is completely bludy pointless because neither of you is ever going to say "fair enough - you are right".

    Enough digging already.

    Mr John the Joiner Number One, I think the OP has said the hole should be deep enough as he tested it with the bare screw. I have used these plugs - correction, I have tried to use these plugs - and they are as bad as he says. I simply couldn't believe how soft they were - unusable. Awful.

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