# Use of Molly/Ancor bolts in drywall



## johnfm3 (Sep 30, 2016)

Ok, I am on my holiday vacation and have planned to start the build of my new layout and this is my first bench work build. Using my stud finder in my recroom on my lower floor exterior wall, I get some strange results. At a few points, I see 7.5 inch studs at places where there is no reason for it. And other times, my stud finder finds a edge then hits the center and remains like that for 18in. Other spots, it finds a edge, holds center for 6in, finds a edge, holds center for 6 in, repeating. Almost as if I have wood panels behind drywall.

Throwing all the above info away, I am considering buying molly/ancor bolts.

E-Z Ancor

They claim 50lb per in drywall and I am considering using 3 per 4ft of wall support.

Has anyone had any luck with using these kinds of mounting hardware to drywall?

Happy holidays,
John


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## gunrunnerjohn (Nov 10, 2010)

If you're going to cantilever a shelf off the wall, my advice is do NOT try to do it with drywall anchors! The real load with leverage out a ways on the shelf will be considerably more than the actual weight. You're liable to find your whole layout on the floor! 

I have the same type stud finder as this Franklin Sensors ProSensor X990, it's worked great for me. You just slap this one on the wall and it actually outlines the studs, no need to insure you don't start on a stud, it figures all that out.

















As for the indications, many times you will find odd stuff behind the walls, including a chunk of plywood. This is especially true of older houses that may have had some modifications over the years.


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## johnfm3 (Sep 30, 2016)

For clarification, I am not doing cantilever layout. The front edge will have legs. And built under the layout will be a free standing cabinet setup not attatched to the layout or wall. In any case, only the surface against the wall will be secured. In the 2 spots in wall corners, I plan for only 1 Leg at the floating corner since the other 3 corners are at a wall.


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## gunrunnerjohn (Nov 10, 2010)

That's less risk, but I think I'd still try to find the studs if it were me. I only use drywall anchors for really light stuff, towel racks, small curio shelves, pictures, etc.


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## johnfm3 (Sep 30, 2016)

Thanks. I found the the stud finder you recommended at my local hardware store. A quick review on youtube has convienced me to buy it. Lets see how this goes.

John


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## gunrunnerjohn (Nov 10, 2010)

I love that stud finder, I gave away the other two I had that were the "old school" wave them around on the wall and try to figure out what was behind it models.


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## JeffHurl (Apr 22, 2021)

Stud finders don't work well on walls that don't have a good size void behind the drywall. If you're in a lower level, it is very likely that the wall is built with furring strips on top of a cement wall. This only leaves a gap of about an inch between the drywall and the cement (or cinder blocks), and many stud finders don't do well in that scenario. I have a feeling your new stud finder will work much better.

Also, Furring strips may not necessarily be 16" on center either.

Regarding drywall anchors, I came across these once when I needed to hang a really heavy mirror. They are very substantial, but I'm not sure if there would be enough space behind the drywall to get it installed if, in fact, your wall is on furring strips instead of 2x4s.

Toggler anchors


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## johnfm3 (Sep 30, 2016)

The house was built in 1978. I thought about concrete behind the drywall, but I have power outlets along these walls measuring from floor at 14in on center. The wall thickness is only 8 or 10in from drywall to siding. Given the thinkness of drywall and the 2 layers of siding, there is not enough for a fare sized concrete wall and stripping to make room for electrical boxes. So I have to assume the concrete only comes up 10 inches or so or my wall studs are secured to the slab directly to be below the electrical boxes.

I have a concrete slab on this lower portion of my house where the layout will be going. The mid section is on a raised foundation. And the upper section is above the lower. My layout is going to be secured for a 40in deck height.


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## T-Man (May 16, 2008)

To verify the stud finder search for drywall screws with a magnet. The old fashion way is to drill holes a half inch apart.


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## Severn (May 13, 2016)

I believe I'd do just about anything to find them there studs behind them walls. I've actually just used the heal of my palm I guess it's called to listen for the change in tone by striking the wall. Which has worked better for me than the one stud finder I had years ago.

But failing that, the stud finder, the magnet for nail heads (which I like this idea), then surely the test holes would work... So Id definitely do this also.

last but least ... you could also remove a carefully cut piece or pieces... If you really wanted to know all the mysteries behind the wall. But that's big job category.


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## JeffHurl (Apr 22, 2021)

johnfm3 said:


> The house was built in 1978. I thought about concrete behind the drywall, but I have power outlets along these walls measuring from floor at 14in on center. The wall thickness is only 8 or 10in from drywall to siding. Given the thinkness of drywall and the 2 layers of siding, there is not enough for a fare sized concrete wall and stripping to make room for electrical boxes. So I have to assume the concrete only comes up 10 inches or so or my wall studs are secured to the slab directly to be below the electrical boxes.
> 
> I have a concrete slab on this lower portion of my house where the layout will be going. The mid section is on a raised foundation. And the upper section is above the lower. My layout is going to be secured for a 40in deck height.


I assumed your wall was below ground since you said lower level. If it's above ground, then you are probably right. The thing is, that every time I've had issues with a stud finder was when there was a lot of density behind the drywall (or a very small void), so the sensor had a hard time figuring out the sudden change in density when you move the sensor over a stud. I suppose heavy insulation inside the wall would do the same thing. Hopefully, your new sensor is better. If not, then try the magnet. Sometimes you can also see a seam in the drywall if you really look for it. Seams will always be on a stud so you can nail into the stud on either side of the seam.


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## sjm9911 (Dec 20, 2012)

I woyld try to find the studs. Since the layout will be on the wall, run a stringer for the length of the wall and screw the train board to its top. You can drill or screw into where you think the studs are, starting at one end of the room and work your way over. The stinger will cover any holes made. Studs should be 16 on center unless its like newer light weight constrution. So once you find one , mesure out 16 inches and check there.


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## CTValleyRR (Jul 26, 2014)

If it's an exterior wall, there is probably insulation behind it that is sufficiently dense to throw off the stud finder.

I have used moly bolts for other applications, and they work quite well. I have a coat rack in my front hall that probably has 100 pounds of more of coats hanging from it, and it's solid as a rock.

That said, I'd try to find studs and use those for this application. The downside of a failure is much higher.


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## sjm9911 (Dec 20, 2012)

I just dont like the idea because of the vibration, however slight it may be. That will loosen the mollys over time, even the really strong self tapping screw type ones. Its just not worth the chance.


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## afboundguy (Jan 10, 2021)

T-Man said:


> To verify the stud finder search for drywall screws with a magnet. The old fashion way is to drill holes a half inch apart.


I personally like the really old school method of knocking and listening to the change in pitch... I had to do this in several of my walls as my house is from 1948 and had a lot of plaster walls so stud finder didn't work well at all...

I'll have to echo everybody else's hesitation about not using drywall anchors for anything other than very light things such as hanging a picture or something similarly light...


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## johnfm3 (Sep 30, 2016)

I use knocking while working with my stud finder to determine if I am getting a odd reading. In this case, I just got home from picking up the stud finder. Interestingly enough, the stud finder is finding the studs are 4x something. So 4x6 or 4x8. And it looks like those are 32 inch apart. In between those are 2x's. Keeping a 16in on center.

Pictures of the start of the build to come. Watch for the build thread.

Happy Holidays,
John


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## gunrunnerjohn (Nov 10, 2010)

Truthfully, while I've used the old "knock on the wall" method more than once, the deluxe stud finder I posted is the greatest thing since sliced bread! It works so much better than the little ones that it's not even in the same zipcode!


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## OilValleyRy (Oct 3, 2021)

If you’re only wanting to secure the corner areas to the wall, then the simplest thing is to french cleat it right at the corner. All corners are double stud minimum, sometimes triple under some circumstances. A simple 1x4 french cleat on each side of the inside corner would hit the double studs.

Studs are not always spaced 16 inches from every corner. They start at one corner and go down the line. They add additional studs where needed, resulting in odd spacing like 9 inch voids etc. That’s not considering they may have made alterations mid way through the build, only to undo/redo the changes. I once did a house where the home owner rearranged the master bathroom three times mid-work. Meaning the lavatory plumbing for sinks & toilet were relocated twice. Felt bad for the plumber but we had it just as bad.

*Worst case scenario *tap in small nails near the floor, above baseboard trim. They’re easy to just leave and paint over when they hit a void. You know the corner has them, so try 16” from there to verify. And nothing verifies as good as physical contact between a nail & stud.

As for the strange results from the stud finder, there’s many explanations, from horizontal reinforcement for water supply lines or a drain/vent line, a footer for a window or in wall AC unit that was long ago removed, a closet that was removed, and a number of other possibilities. It may be that the drywall is indeed laminated over original wall material, or a variation of materials there. My home was built in 67 and has cement board walls covered in plaster, which was likely coated in lead-based paint. Between the plaster & cement board, a stud finder is useless.
If you have laminated material (i.e. double drywall) you’ll be able to tell by removing a receptacle cover plate. The receptacle will have been removed and an extension ring installed, then the receptacle reinstalled. Fun fact, you can determine if you have hardwood flooring under carpet the same way by removing a heat register & looking at the layers along the opening. Entirely unrelated to this, but a clever way of determining.


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## Don F (Dec 5, 2015)

Nail pops and black circles on the walls are an indication of stud locations. I have taken baseboard molding off as a last resort to locate studs.


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## Ron045 (Feb 11, 2016)

This thing looks cool. If you just want to see it in action just start around the 4:00 mark to see it in action.

Walabot DIY 2 review: stud finder for your phone. BEST STUD FINDER! #WalabotDIY2 [355] - YouTube


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## johnfm3 (Sep 30, 2016)

Ron045 said:


> This thing looks cool. If you just want to see it in action just start around the 4:00 mark to see it in action.
> 
> Walabot DIY 2 review: stud finder for your phone. BEST STUD FINDER! #WalabotDIY2 [355] - YouTube


I know about this and want one so bad. Sadly I did not prepare well enough to think I might need this. Yet I bought my self leveling bosch laser level for this project. Mixed up priorities... lol


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## johnfm3 (Sep 30, 2016)

Well, all in all, attaching the layout to the wall was a bust. My one walls is a total enigma. I used my stud finder, as well as the Franklin with some really odd results. Including the result of every where there was a stud identified, I would drill a pilot hole into air. Even stranger, when pulling the drill out, no insulation is coming with it. The drill bit is not even packed with foam. 

The Franklin stud finder shows horizontal and vertical studs. And is showing alot of 6 in wide studs.

For the majority of the wall, knocking returns a more hollow sound. And every 4 ft a firmer sound. Possibly where the drywall meet.

The results are so messed up my wife is authorizing me to cut a 1in horizontal slit the length of the wall to get a view into whats going on. There are some issues with the house, and my father n law and I have some theories which he really is leaning on.

With all this, molly bolts are really not an option, and I can not fasten to studs, I am switching over to building a free standing layout.

Happy holidays,
John


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## sjm9911 (Dec 20, 2012)

Wow, if it is really like that, its not good. So , eaither turn a blind eye and deal with it later if ever or open it up and deal with it now. If opening it up you could get more of a surprise then you want. Good luck and I hope its nothing bad.


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## OilValleyRy (Oct 3, 2021)

Tap a thin nail in low to the floor about 2 inches out from the corner. It will hit a stud. Measure 16 inches from that & tap in another to confirm the 2nd stud, and so on. Nail holes are easier to cover ip than a long slit, especially panelling nails.


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## gunrunnerjohn (Nov 10, 2010)

Ron045 said:


> This thing looks cool. If you just want to see it in action just start around the 4:00 mark to see it in action.
> 
> Walabot DIY 2 review: stud finder for your phone. BEST STUD FINDER! #WalabotDIY2 [355] - YouTube


I think that's more of a gimmick than a great advance.


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