# 2x Furring on block



## Tom M (Jan 3, 2007)

I need to attach 2x on the flat to hollow block. Tapcons, treated, adhesive....... easy but what if you dont want to use treated?

Tar paper behind regular fir and tapcons? Going to put extruded foam in between the stud and no I dont have the space to strap over foam.


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## Tinstaafl (Jan 6, 2008)

The idea behind using PT against masonry is that it's more moisture-tolerant than untreated. While felt would give you some protection, it's not really waterproof--just has variable permeability.

Plastic would probably be better, but still wouldn't stop moisture around the fasteners, whether tapcons, cut nails or whatever.

I'm curious as to why you don't want to use PT.


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## Tom M (Jan 3, 2007)

Its above grade. The corrosion factor with electric boxes and construction fasteners


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## Tinstaafl (Jan 6, 2008)

Damned if you do, damned if you don't. I've seen plenty of furring like that decades old, with no protection at all and still in good shape. Above grade, I wouldn't have a problem with it.

But if it's getting inspected, my guess would be that the PT requirement will trump any concerns about the fasteners that are going to be used on it.


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## Tom M (Jan 3, 2007)

Actually had spruce furring with 3/8 and paneling.


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## TheConstruct (Dec 8, 2017)

Joist tape would eleviate some or most of the concerns about moisture at the anchor locations. Is the block wall new? I cant imagine moisture being an issue either way.


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## TheConstruct (Dec 8, 2017)

Plastic electrical boxes and stainless drywall screws would be an easy fix if you do go PT


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## griz (Nov 26, 2009)

i am providing some free technical advice to a neighbor redoing his garage/basement.

2x4 pt ramset to block walls, metal elec boxes & romex staples.

about 25 years old.

no evidence of corrosion on shot pins, elec boxes or staples.


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## Calidecks (Nov 19, 2011)

griz said:


> i am providing some free technical advice to a neighbor redoing his garage/basement.
> 
> 
> 
> ...




Yep, just need to make sure you use the right load. 


Mike.
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## Rio (Oct 13, 2009)

griz said:


> i am providing some free technical advice to a neighbor redoing his garage/basement.
> 
> 2x4 pt ramset to block walls, metal elec boxes & romex staples.
> 
> ...


If it's 25 years old it's probably the type that used arsenic (CCA) and not the copper treated stuff that's so potentially corrosive.

Regarding the Op I think felt would be fine or the joist tape and probably as Tin stated nothing would probably work also. Galvanized Sheet metal will work also.


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## Tom M (Jan 3, 2007)

So its not new but the rock had mold everywhere, none on the block but throughout on the rock. Lack of ventilation. They used two exhaust fans prior for air. Had an engineer come out for cutting out windows and enlarging a door but even then those windows wont be open often. We are killing wall AC and electric heat in favor of a ductless heat pump so mechanical conditioning.......


I have 5/4 spruce furring that we were going to pad out with 1/2 and then 2x4 flat on the new areas to blend in. My concern was the spruce looks great but the rock was moldy with a hollow wall cavity. I go sticking foaming in between and I no longer have that bit of drying.


If the walls were poured I would hilti the 2x but with hollow block the bounce I fear will jiggle them loose. the 2x is thicker than the cell wall or close.


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## superseal (Feb 4, 2009)

Foam first, then apply furring...done deal. I'd probably use foamular...it's slightly vapor permeable over foil faced.


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## Fishindude (Aug 15, 2017)

Could go with galvanized metal furring.


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## Tom M (Jan 3, 2007)

Don't have the space to follow the presciptive building science to the letter.


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## Windycity (Oct 3, 2015)

Can you use the foam with the groove for the furring strip?

https://www.homedepot.com/p/Owens-C...oam-Board-Insulation-Sheathing-43WD/100320293


Sent from my iPhone using Tapatalk


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## Tom M (Jan 3, 2007)

I could use something like that. I have to see this is actually a municipal job and there is no plans believe it or not and I don't want to put myself in a position of specifying materials.
The construction official made casual recommendations but I didn't like what I heard.


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## TimNJ (Sep 7, 2005)

Fishindude said:


> Could go with galvanized metal furring.


I was going to say why not use 1 5/8" metal studs to frame out the wall?


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## Tom M (Jan 3, 2007)

I actually priced the job in the event we needed framing so I planned metal studs butted up foam but due to close door framing the build out becomes too much encroachment. 



Plus their is a desire to take advantage of what already in place. My concern was what wasnt a problem before may become one later. Just me being anal


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## Calidecks (Nov 19, 2011)

Are metal studs electroplated? Not sure if that's sufficient galvanization. For ACQ anyway.


Mike.
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## Rio (Oct 13, 2009)

They are electroplated, have different plating thicknesses, maybe go with G90, would check to verify with the manufacturer.


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