Pocket Holes... into masonry?

[Copes]

Hi Guys,

I'm working on some alcove shelving in my new house, and to tell the truth it's been a nightmare project from the off.

Basically i'm using invisible shelf pins along the back, going into solid timber. After a lot of trial and error i've gotten one set of the shelves up, because of the shelf pins they need to slide straight into the alcove (which in a house over 100 years old) the walls are all over the place, so i've had to do a fair bit of encouragement to get them in place.

Now that they're all in (and i don't think they're coming back out anytime soon.) a couple of them seem a bit wobbly on the very front edges. Maybe wobbly is the wrong word but they do have more play than i would like with a little weight.

I've been trying to figure out a solution to this, but i don't want to put in brackets or anything that will be visible on the final shelves that isn't shelf or wall.

So i thought maybe i could drill pocket holes into the front undersides, then once the angle is there, drill right through and into the walls. Then either put a small wallplug (if possible.) or fill the drilled hole in the wall with somekind of filler, then drill in a screw with a large head to somehow snag into the wood, or atleast give it a little bit of support...

I know it's all a bit sketchy, but i thought maybe someone has any ideas that might work?

Cheers fellas.

 

[blackrodd]

Hello and welcome. You don't say what material you're shelves are made of .
If you can post 5 posts, (I think it is) perhaps you can put up some pics for members to understand fully you're situation.
Regards Rodders
PS

Is this the sort of fixing you used? http://www.ebay.co.uk/gds/Installing-Sh ... 533/g.html

Or this? http://www.ebay.co.uk/bhp/concealed-flo ... t-brackets

RODDERS

 

[Copes]

Hi Rod,

First link is spot on.

The material is 27mm pine furniture board.

I'll try and clarify what i mean;

Essentially i've used the mention shelf pins, drilled two holes into the back of the shelves and cut the board edges to match the wall profiles they're now a bit of a wedge shape /______\ (from the top). I've then inserted them onto the pins and with a bit of persuasion with a mallet, got them stuck in place.

However one of them just seems a bit flimsy as in you can move the front up and down slightly. I can't seem to get them back out, they seem stuck, and are flush to the back wall.

All i want to do is basically attach them in an invisible means to their front edges, to secure the front face so it can't be moved up or down. So i thought pocket holes would be perfect, as they can be drilled in place.

I don't know if it would work, but if i say used the pocket hole jig, then where the screw usually cut its own hole through, drilled a smaller hole and then used a masonry bit to drill that hole into the wall, would a long coarse pocket hole grip into the masonry?

Or i thought possibly drill the pocket hole, then drill out the inside, drill the masonry hole, pop in a plug and pop a screw in, it wouldn't "press the wood to the wall" but i juts need the vertical support it would offer, not the joining strength...

I might be going down the complete wrong track, but i'm stumped!

Thanks for your help.

Mark

 

[rdesign]

don't see why it wouldn't work just drill a pocket hole in the shelf then use a masonry drill plus long pit throughout that whole into the wood
if needs be widen the wood hole to let a "screw with raw plug already started on it"through, hammer into the drilled hole then screw till tight should give enough support for what u need don't over complicate it.

 

[blackrodd]

Sorry. I missed this yesterday!
Sounds like it is the only way to overcome you're predocament.
Rather than trying to force a red plug in without damage owing to the size,
Consider driving a smaller,yellow plug in first and follow it with a decent "whittled" wood expander which you can cut off.
It also may be a good idea to try this lower down the same wall and see what plug is the best size and the sequence
of drill change over etc.
You can fill in the hole with polyfill after.
Regards Rodders

 

[woodenstx]

Id use spax screws that you can drive straight into masonry without need for a rawlplug etc.

 

[Copes]

Thanks for all the advice guys, really interesting.

I think i like the sound of the spax masonary screws, i'll be honest i never know you could even get masonary screws.

What length of screw would you guys recommend? I guess there will be a fair length of the screw actually in the wood, as it's 27mm thick wood, will mean the pocket hole is fairly set back from the edge.

I guess the more screw into the wall, the more stable it would be? would something like this be a good choice? 7.5x152mm concrete frame screw? I can't use links on posts yet so if you fire that into ebay, you'll see the ones i mean.

Cheers guys

 

[paulrockliffe]

I think if you get one screw in close to the edge on each side that should be all you need. I'm not entirely clear how much access you've got, can you lift the shelf upwards enough to get a drill to any part of the wall where the shelf will sit, or are you having to drill through the shelf to get at the wall?

If you're drilling through, the problem you have is that you'll generally need a wider hole in the masonry than you want in the wood because of the plugs etc. I've never seen or used a masonry screw, if that would work then it sounds easiest. Another thing to consider would be drilling a small hole in the wall, injecting it with resin, then firing a screw in. You'll want some thread to bite the wood for this to work best as there won't be any bite in the masonry until the resin cures.

If you could wiggle the shelf out of the way enough you could screw horizontally, chisel out the shelf so it sits over the screw head and then fill over the screw head to hide it.

I'm about to do the same as you and have gone for a 2" x 1.5" front piece in solid timber, with veneered ply top and bottom to sandwich a softwood frame. I'm doing it that way because my house is as bent as yours and the sandwich allows a much easier construction and support. AS well as being a lot cheaper.

 

[Copes]

Looking at hte kreg screw selector, it recommends 38mm screws, for using 28mm material, and the screw protrudes 21mm out of the wood, so if i went for say 100mm screws, i'd get 79mm~ into the wall which sounds reasonable to me.

The shelf "wiggles" but not enough to get enough clearance to drill and fit a plug, so it's going to have to be through the pocket hole.

I did consider using filler or resin to fill the hole too, that may still be an option but by the sounds of it, if masonary screws will work they sound the easiest and although most of them are countersink heads, it shouldn't matter as i'm not really interested in the pulling force anyway.

in hindsight i really wish i'd build a torsion box type of shelf, even though it would have ended up thicker, it would have been a million times easier to put in. (the wife wanted thin shelves.)

I'll let you all know how it goes!

Cheers

 

[paulrockliffe]

Would a nail gun work? Never played with one, so no idea, but it would be fun trying it out!

 

[Copes]

Hi guys,

Just thought i'd let you know how it all went... Suprisingly well is the answer!

It was a slightly long winded process,

- I drilled all the pocket holes at the appropriate distance from the edge.
- I drilled out the end of the pocket hole with a 7mm brad point, exposing the wall.
- I then drilled the masonry with the supplied 6.5mm bit, i ended up using a drill bit extender to get the the required depth because of the angle and my drill chuck getting in the way.
- I then discovered the end of the 105mm masonry screws didn't fit inside of the pocket hole (doh.)
- I used a counter sink to then enlarge the pocket hole entrance to accomodate the screw.
- and all done!

I was really suprised by just how sturdy the shelves now feel, they're rock solid. i was planning on putting a screw in the middle of each shelf as well, but i've left it at just the edge ones.

Thanks for all the help, and hope this helps someone in the future!

 

[blackrodd]

I'm pleased it has worked out quite well in the end.
Regards Rodders