[bostonwindows]

I am making a picnic table using 21/2" screws and almost every time it cracks the wood??? How come???

 

[wood_chucker]

Try predrilling the holes.

 

[Anguspapa]

Drill pilot holes! They have tapered drill bits for that exact thing. Good luck

Sent from my iPad using Wood Forum

 

[Steve Neul]

How close to the end of the boards did you put the screws? A lot of times if you put the screws within 2" of the end of a board the wood will split even if you predrill pilot holes. The wood type can also play into it. If you are working with a wood like yellow pine it is more prone to split.

 

[bostonwindows]

I am working with pt wood.. I try going slow, and not too close to the edge and still it splits, any ideas?? Or do I need to prolly drill??? Ever hole??

 

[bostonwindows]

Tapered drill bits??? Would that help?? What are those??

 

[bostonwindows]

I just pulled it up on the web very cool, how much small do I go than the screw???

 

[del schisler]

I just pulled it up on the web very cool, how much small do I go than the screw???

i use dry wall screw's all the time , i would say up to 1 1/2" i use a number 5 over that i use a number 6 work's for me , i use a taper drill bit and counter sinker all in one bit, i use only fuller mfd., bit maker only, the other's are inport's and are not any good in my book , http://wlfuller.com/html/countersinks.html

 

[bostonwindows]

This is going to be outside alot, is Sheetrock screws okay for outdoors??

 

[Dave Paine]

This is going to be outside alot, is Sheetrock screws okay for outdoors??

Yes if you want these to immediately rust and stain the wood and perhaps break as the wood moves with moisture.

For outdoor furniture you should use good quality decking screws which are designed for outdoor service so have some kind of anti-corrosion finish/coating. Some galvanized, some other method.

 

[bostonwindows]

What you think about the tapered drill bits, would this help from splitting?

 

[Dave Paine]

What you think about the tapered drill bits, would this help from splitting?

These may help, but I have never used one. I just use a straight bit with a diameter = the inside diameter of the screws (bottom of thread on one side to bottom of thread on the other side).

The deck screws I use for outdoors have a very slight taper, compared to normal wood screws.

I always pre-drill when screwing, whether PT or other wood.

It the screw feels too tight when being driven into the wood, try a slightly larger diameter bit.

 

[4DThinker]

If you want the holes flush or below the surface then countersink or counterbore respectively first. Then predrill a hole the rest of the way through the top piece that is slightly larger than the screw shaft. The screw should not thread into the top piece. Next drill a hole into the piece you want to attach the top piece to. Use a bit that is a couple sizes smaller than what you used for the top hole.

 

[BZawat]

Sheetrock screws are certainly NOT ok for use in pressure treated lumber. The chemicals that the lumber is treated with will literally eat the screws. You'll need coated screws made for use in PT lumber. "Deckmate" is the brand that comes to mind.


http://m.homedepot.com/p/DEWALT-3-Piece-Steel-Countersink-Set-DW2535/100531905

These are the best readily available countersink bits you'll find, in my opinion. The drawback is you gotta buy the 3 pack unless you order online from DeWalt. The #8 size will fit your PT deck screws perfectly. Also don't over-drive the screw. Stop when the head is just below flush with the surface. That will definitely alleviate your splitting problem.

 

[Quickstep]

I use stainless steel screws in anything outdoors. They're expensive, but worth it because they don't get dissolved by the new treated lumber and they don't corrode and stain. These have a drill point that helps avoid splitting, but pre-drilling is the best defense. The square drive is nice too. They come in a normal size head and trim varieties.

http://www.grabberman.com/ItemDetai...=+L2P3MIyRNPZk0xBscqzuoABX4bkdoXGGAwW/MI4U7c=

 

[dodgeboy77]

Along with drilling pilot holes, if you want to save a load of time driving those long screws, get a cordless impact driver - here's an example:
http://www.homedepot.com/p/Ryobi-18...-Driver-Tool-Only-P236/100049838#.UeiwYm0piaQ

Also, from what I've seen, screws that work with pressure treated lumber will specifically say so on the box.

Bill

 

[jharris2]

Definitely drill countersunk pilot holes.

Even then flat head screws taper down from the head to the shank.

If you over tighten these screws the head acts as a wedge and is more likely to split the wood.

Just drive the screws until they snug up into the counter sink then give them a turn with a manual screwdriver.