This is a true novice question! I live in a home constructed with a concrete (slump) block
exterior. The contractor used 2x furring on the inside nailed to the block as a foundation
to attach the interior drywall. House was built in the mid 70s.
In all of the remodeling I’ve done, I’ve never gotten the hang of nailing these furring strips
to the block. Almost every time I nail I crack the block resulting in a situation where the
nail has no hold and, at worst, one which substancially cracks the block, probably weakening
it’s structural function. I use the same nails and size that the original contractor did.
So I must be doing something wrong. Can anyone give me a 101 crash course in how
to do this correctly.
Thanks,
Glenn
Replies
tapcons
I second the tacons. Just get 2 drills (one hammer and one preferably a impact driver) and get a system going. You'll have no worries about bent nails and broken blocks.
Chuck
I am thinking maybe the concrete was still soft enough at the time. Now it's cured and harder to nail into. As suggested, try screws or try hanging things off the joist. Masonary nails and power actuated gun nails rusted quickly in my basement. Tapcons are still holding and I don't see any rust stains around them. Hope this helps.
http://www.tapcon.com
Lets make this unanimous. Tapcons are great for this kind of thing. I use my small bosch rotary for the holes then a standard drill to screw in the tapcons.
The tapconshold so well that its usually no problem countersinking the tapcons so the head wont interfere with the drywall install.
I have fastened many a furring strip to block and concrete with steel cut nails. I did this long before I bought my first power actuated fasteners.
Anyways, the key to nailing cut nails is to use the proper length. 4d cut nails are all you usually need to hold a furring strip. Sometimes 6d's are called for. Normally 8d's are too big. The round masonry nails sometimes are easier to work with in the same sizes. Aim every nail into the mortar joints, not the block. Also, be sure there is no play behind the furring strip. If it is bouncy before you start nailing, the play in the member will dampen the energy of the hit and the chance of a well nailed furrstrip is greatly diminished.
The next order of business is the hammer and the delivery. The energy delivered must be sharp and heavy enough to drive the nails into the concrete. You can't coax them in....you have to be firm with every blow. Not too firm, not too soft and the hammer must have some weight and length. This is one area where I didn't like my titanium 140z framer. It would drive a spike fine but didn't have the hitting power to properly drive in a cut nail or masonry nail. I was skilled, so I could get them in but not without some extra effort.
Lastly, I found that using the hardened Hilti (and others) pins was usually easier than the cut nails and masonry nails. If you are still having a hard time doing all the things right, these pins might be your solution.
Note, if you are going to fasten the furrings with 4d's, use a series of 3/4 daubs of construction adhesive, 6" oc.
Bob's next test date: 12/10/07
I use my framing nailer and case hardened nails just for furring to concrete block. Hit the joint and those strips are there for eternity. Last time I bought a box it was about $115. No telling what they are now.
What size are the case hardened nails. That sounds like a good system. I haven't furred anything of substantial amounts in dozens of years but out here, we never know what is coming next. Bob's next test date: 12/10/07
My supplier, Fastening Systems, has them is two lengths. I was shooting standard 1x furring over 3/4" or 1" Polyiso, using 2 1/4" nails. You can use that length on new block applying furring only but 40-50 yr old block (mortar) will bounce your gun hard enough to hurt and often leave the nail proud by 3/4". Switch to the shorter length (1 1/2") for straight furring. The 2 1/4" nails are also great for 2x furring
Tapcons are nice, hold forever and you don't have to hit the joints but covering large areas is too time consuming and very expensive. I use them where there is chance of blowout, such as window and door openings, where repairing blasted block would be a pain, although I use wider 1x4 or 1x6 in those areas and can hold the nail back from the edge.
Good tips. Thanks. Do you have to crank up the air in the gun or does your normal settings work? Bob's next test date: 12/10/07
I never have messed with the pressure setting, just the depth. I run my guns wide open.
In the past I've tried pressure regulation but only on the finish guns. I think framing guns work best when you allow the depth setting to set the nail head depth while allowing the full power of the tool to drive the fastener through whatever density material you are using.
I always ran the guns wide open too. I think we always set our air at 120. Sometimes, we'd have to adjust the factory settings on the regulators to get more. I think the hoses constricted a lot of the presssure and we weren't getting anywhere near 130 at the gun even if we had it set that way. Bob's next test date: 12/10/07
Many thanks for all the rapid replys.
Tapcons it is.
Glenn
We do a lot of this because we use mostly block basements. I have a Bostitch gun that shoots hardened T-Nails. It looks like the same body as their flooring nailer.
We have an air caulking gun that we use with quart sizes of construction adhesive. We run a bead on the back of the strip, stand it up and shoot it to the wall.
We rip styrofoam to 14 1/2" widths on the tablesaw and set them in place next to the strip you just installed. This makes a perfect spacer. Then just install the next strip against the foam.
It is very fast and makes for nice, even and plumb nailers.
Glen,
Not sure what a "slump" foundation.
If you have a typical block foundation you dont want to nail into the block, you want to hit the mortar joint.
furring to block
Use a 1/8 inch masonry bit with cordless hammer drill or small corded hammer drill not one that will shatter block and 1 1/2 concretenail not cut nail it's black believe carpet guys use to nail tack strip work great
furring to block
Use a 1/8 inch masonry bit with cordless hammer drill or small corded hammer drill not one that will shatter block and 1 1/2 concretenail not cut nail it's black believe carpet guys use to nail tack strip work great