Sloppy contractor shortcuts

[mrramsey]

So I have a bit of a peave that rattles my chain pretty good. My contractor that is doing the install of my HotDawg installed two pieces of unistrut on the ceiling to hang the unit. He used 1-3/4" x 3/16" Tap-Con screws!

That's 1" of penetration into the wood floor joists above with screw threads that are not designed to bite into wood. Since the job was stalled due to a mis-ordered part I took the liberty of redoing the unistrut using 3/8" x 3-1/2" Lag screws.

 

[Shootinok]

Eh - there'll hold long enough for him to get paid...

That is one thing that gets under my skin too.
Craftsmanship is a dying art. If you do find good guys, spread the word - and pay them.

 

[D45]

First they order the wrong vent kit and now they use very short Tap-Cons (concrete?!) screws........

Did you bring this to the installers attention, before having to do the work yourself?

How did you find this place? How much is the install?

 

[fartymarty]

Hmmm...shows how little I know, I always thought that unistrut was installed with threaded rod going up through the dry wall into more unistrut sitting on top of the rafters.
I'd never make it as a contractor that's for sure.

 

[Bert_]

One of the the uses the manufactures list for tapcons is in wood...

 

[D45]

One of the the uses the manufactures list for tapcons is in wood...

Definitely not 1-3/4" long

 

[BonzoHansen]

My whole house was wall papered from day one by the builder, we bought it years later. When I pulled the wall paper down in a hallway I found they papered over a hole right at the ceiling joint - and under the crown trim. So i had the pleasure of fixing that too.

 

[mrramsey]

One of the the uses the manufactures list for tapcons is in wood...

Attaching a piece of wood to concrete, yes. but not wood to wood.

 

[mrramsey]

Hmmm...shows how little I know, I always thought that unistrut was installed with threaded rod going up through the dry wall into more unistrut sitting on top of the rafters.
I'd never make it as a contractor that's for sure.

Yes that is one application, laying perpendicular to wood members from the top side.

 

[mrramsey]

First they order the wrong vent kit and now they use very short Tap-Cons (concrete?!) screws........

Did you bring this to the installers attention, before having to do the work yourself?

How did you find this place? How much is the install?

No I didn't. I fixed it after I stewed a bit on the mis-order. They are giving me a hefty credit. I also made some framing modifications where the vent penetrates the wall so that there is significant structure for attachment points. .

 

[brewchief]

A #10 wood screw has a pullout force of over 120lbs per inch of imbedment in spruce-pine-fir, 4 of them would be around a 5-1 safety factor with an 85lb hot dawg. A 3/16 tapcon would be a touch larger but has a different thread design, the difference in thread design could be the deciding factor but the few times I've used a tapcon into wood they have held very good.

I prefer to use one of the newer type structural screws that have an engineered rating over an ungraded lag bolt, I wouldn't have used a tapcon but I bet it would have worked fine for the life of the heater.

 

[TractorJeff]

1" into a wooden joist is plenty to support an 85lb heater. Especially as it was probably more than one screw!

 

[vavet]

A #10 wood screw has a pullout force of over 120lbs per inch of imbedment in spruce-pine-fir, 4 of them would be around a 5-1 safety factor with an 85lb hot dawg. A 3/16 tapcon would be a touch larger but has a different thread design, the difference in thread design could be the deciding factor but the few times I've used a tapcon into wood they have held very good.

I prefer to use one of the newer type structural screws that have an engineered rating over an ungraded lag bolt, I wouldn't have used a tapcon but I bet it would have worked fine for the life of the heater.

This is going to come out the wrong way, but I’ll ask anyway. Can you cite your source on this? I’m not doubting or challenging you. I’m curious what effect screw diameter has.

 

[brewchief]

This is what I went by(if my link works)



https://www.google.com/url?sa=t&rct...Pull-out.pdf&usg=AOvVaw2BKmZsBLk_qnMxaT0L1PkZ

 

[mrramsey]

Two turns on the tapcon and they pretty much fell out. I for one prefer at least a 2x the material thickness for penetration. These heaters vibrate albeit minimally.

 

[bobbyjean]

wow...sorry to hear..good that you caught that now...how did the chimney work out ?

 

[mrramsey]

TapCon gives ZERO specification for installing into wood (at least that I found) They have great shear and tension values in concrete but they also stste the following - "A safety factor of 4:1 or 25% is generally accepted as a safe working load" I also read this in another document as 25% being the static load.

My point to the thread was really to highlight using the right tool (screws) for the application. So the fact that there is not any data to support using the Tapcon screws in this application. Would it have held? Who knows but when I have 85lbs hanging over a walk area with family and friends walking through I'd rather spend a couple dollars on the right one.

 

[mrramsey]

wow...sorry to hear..good that you caught that now...how did the chimney work out ?

Waiting for the new kit to come in. Install will resume on Friday.

 

[Dragfluid]

Hell, I just tossed a couple of 2x4's up over the trusses and ran my threaded rod through them. Like has been stated, there's a little bit of vibration involved here. I want it up there for life, so I went all out and spent an extra $2.00 for the 2 pieces of 2x4.

 

[mrramsey]

Hell, I just tossed a couple of 2x4's up over the trusses and ran my threaded rod through them. Like has been stated, there's a little bit of vibration involved here. I want it up there for life, so I went all out and spent an extra $2.00 for the 2 pieces of 2x4.

That works perfectly fine. I am dealing with living space above so this was not an option for me.

 

[yeldogt]

1" into wood is a good bite .. especially with what must have been 4 screws.

What diameter tap cons .....

 

[mrramsey]

1" into wood is a good bite .. especially with what must have been 4 screws.

What diameter tap cons .....

3/16" . The threads on tapcons are not designed for wood. 1" penetration will depend on the application For a Tapcon 1" into concrete or a CMU, great, for wood no thanks.

 

[PelicanPines]

Had a tile company do a bathroom when I built my house, I was too busy... the installer was the owners brother... I asked him which caulk he was gonna use between the tiles and tub... he looked at me and said... for speed we just grout that so it color matches...

FWIW always use CAULK between dissimilar products. If you don't know that... you have not watched enough building shows on TV.

 

[yeldogt]

3/16" . The threads on tapcons are not designed for wood. 1" penetration will depend on the application For a Tapcon 1" into concrete or a CMU, great, for wood no thanks.

"Design" is an interesting word --- there are many designs for screws into wood. If you look at the overall spacing of the large threads they mimic a true old school wood screw .... in effect thats what the screw is trying to do in concrete ... vs the way a metal screw is designed to go into a plastic anchor.

 

[Bert_]

Nuff said

I would agree it would be nice to see a longer screw, but 1" would have been fine.

 

[Dragfluid]

You guys are forgetting that it's not going into the wood 1" due to whatever is between the wood and the screw head.

 

[brewchief]

You guys are forgetting that it's not going into the wood 1" due to whatever is between the wood and the screw head.

They were 1 3/4" screws so with 1/2" drywall and about 1/8" for the strut it should have been pretty close to 1"

I can see with only 1" in the wood it would be pretty easy to overtighten and "strip out" the wood.

 

[mrramsey]

Nuff said

I would agree it would be nice to see a longer screw, but 1" would have been fine.

Thanks for posting that Bert. The screw strength would be fine in tension. Had he used a 2-1/2" I would have let it go. I backed these off 1/4 turn and they all but fell out. Perhaps he over tightened them but either way the ones that were installed would have failed.