Dark Gypsum Asheville NC

The construction is 4-in. brick masonry walls with 4-in. concrete masonry backup. The interior has light gauge steel hat channels attached to the concrete masonry with rigid insulation between the channels.

Preferred Carpet One
(704) 271-1397
5001 South Boulevard, Suite E
Charlotte, NC
Services
Product only, or product plus installation. Hardwood floors: All species and types, solid and engineered, unfinished and prefinished laminate floors, cork floors and bamboo floors; hardwood sanding and refinishing. Other flooring: Marmoleum, sheet vinyl, luxury vinyl V.C.T., rubber floors, cove base. Carpet: All carpet types for residential and commercial; custom area rugs, stair runners and outdoor carpets. Stone: Travertine, slate and exotic stone, granite floors, ceramic, porcelain, glass til
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Homeowner Approved, Allen Tate Concierge Services.

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R & R Masonry Inc
(336) 886-8930
1121 Tangle Ln
High Point, NC
 
Nichols Brick & Tile
(910) 494-8183
1711 Eastover St
Fayetteville, NC
 
American Chimney Sweep Co A
(919) 467-5088
303 Trappers Run Dr
Cary, NC
 
Sanderosa Gardens
(910) 483-9166
3861 Sanderosa Rd
Fayetteville, NC
 
D & D's Flooring & Interiors
(704) 684-4887
628 West Morehead Street
Charlotte, NC
Services
Formerly The Plywood Mart, Inc.; Mohawk® carpet, hardwood, laminate, resilient and tile flooring; Shaw® carpet, hardwood, laminate, resilient and tile flooring; Armstrong® hardwood, laminate and resilient flooring; Bruce® hardwood flooring; custom site finished hardwood floors (custom colors and designs available); Daltile® tile and stone; Crossville® tile and stone; Florida® tile and stone; Marazzi USA® tile and stone; Andersen® windows and doors; Marvin® windows and doors; Santa Cruz®
Membership Organizations
Homeowner Approved, National Wood Flooring Association Member.

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Bill Ibison Stone Company Llc
(919) 851-3835
2509 Piney Plains Rd
Cary, NC
 
A Garcia Masonry
(336) 886-6489
114 Hedgecock Rd
High Point, NC
 
Southeastern Concrete
(910) 764-0100
1001 S Reilly Rd Ste 261
Fayetteville, NC
 
Custom Works Of Fayetteville
(910) 485-3770
8140 Cliffdale Rd
Fayetteville, NC
 
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Dark Gypsum

Provided By:

Source: MASONRY CONSTRUCTION MAGAZINE
Publication date: November 1, 2008

By Norbert V. Krogstad

What causes the dark vertical lines that occur on gypsum wallboard installed directly over the furring strips in brick veneer/concrete masonry walls?

The construction is 4-in. brick masonry walls with 4-in. concrete masonry backup. The interior has light gauge steel hat channels attached to the concrete masonry with rigid insulation between the channels. There is a vapor barrier over the insulation and hat channels. The gypsum wallboard is anchored to the hat channels on the interior face of the vapor barrier.

We were originally thinking that the problem was associated with leakage through the masonry. However, the building has large overhangs and during most rains the water doesn't even get to the brick masonry. Also, the vapor barrier would stop any moisture that did get in the masonry from reaching the interior wall board anyway.

How can this problem be avoided?

The darkening of the gypsum wallboard over the hat channels is sometimes referred to as “ghosting.” This phenomenon is typically caused by condensation from interior air during cold weather.

Because the insulation was placed on the interior side of the concrete masonry, both the concrete masonry and brick masonry are cold. The hat channels interrupt the insulation and are in direct contact with the cold masonry walls.

Click here to read full article from Masonry Construction