Question? Just ask us!
Free Encyclopedia of Building & Environmental Inspection, Testing, Diagnosis, Repair
InspectAPedia ® Home
AGE of a BUILDING - how to determine
AIR POLLUTANTS, COMMON INDOOR
ASBESTOS IDENTIFICATION IN buildings
BASEMENT HEAT LOSS
BATH & KITCHEN DESIGN GUIDE
BOOKSTORE - INTERIORS
BUILDING SAFETY HAZARDS GUIDE
CABINETS & COUNTERTOPS
CARPETING & INDOOR AIR QUALITY
CASEWORK, CABINETS, SHELVING INSTALLATION
CATHEDRAL CEILING INSULATION
CATHEDRAL CEILING VENTILATION
CEILING FINISHES INTERIOR
CEILINGS, DROP or SUSPENDED PANEL
CEILINGS & WALLS, PLASTER TYPES
CEILING TILES ASBESTOS CONTENT
CHINESE DRYWALL HAZARDS
CONDENSATION on WINDOWS & SKYLIGHTS
DRYWALL INSTALLATION Best Practices
FLOOD DAMAGE ASSESSMENT, SAFETY & CLEANUP
FLOOR TYPES & DEFECTS
FLOORING MATERIALS, Age, Types
HOUSE DOCTOR, how-to be
HOUSE PARTS, DEFINITIONS
HUMIDITY LEVEL TARGET
INDOOR AIR QUALITY IMPROVEMENT GUIDE
INSULATION INSPECTION & IMPROVEMENT
KITCHEN DESIGN GUIDE
KITCHEN VENTILATION DESIGN
LIGHTING, INTERIOR GUIDE
METAL LATH, PLASTER & STUCCO
MOISTURE CONTROL in BUILDINGS
NOISE / SOUND DIAGNOSIS & CURE
ODORS GASES SMELLS, DIAGNOSIS & CURE
PAINT FALURE, DIAGNOSIS, CURE, PREVENTION
PLASTER TYPE IDENTIFICATION
SAFETY: Elderly & Veterans Home Safety
SEWAGE BACKUP TEST & CLEANUP
SOUND CONTROL in buildings
STAIN DIAGNOSIS on BUILDING INTERIORS
STAIRS, RAILINGS, LANDINGS, RAMPS
THERMAL TRACKING & HEAT LOSS
TRUSS UPLIFT, ROOF
VAPOR BARRIERS & CONDENSATION in BUILDINGS
VENTILATION in BUILDINGS
WALL FINISHES INTERIOR
WATER ENTRY in buildings
WINDOWS & DOORS
WINTERIZE A BUILDING
WOOD Burning Heaters Fireplaces Stoves
WOOD FLOOR DAMAGE
Arching roof truss uplift: here we provide a definition of arching roof truss damage or roof truss uplift and we explain why truss uplift occurs, where truss uplift cracks will appear, and how roof truss uplift cracking can be avoided or corrected. Roof truss uplift can be diagnosed as the cause of nail pops and cracks or separation between the ceiling and wall top.
Arched roof trusses, moving in response to moisture & temperature variations across the truss, can lift the building ceiling sufficiently to cause nail pops or actual tears at the ceiling-wall juncture. This article explains why arching trusses happen, where the damage will appear, how to recognize it and how to prevent it from recurring.
Green links show where you are. © Copyright 2014 InspectApedia.com, All Rights Reserved.
Roof Truss Uplift and Cracks or Ceiling Nail Pops: Details of Truss Uplift Cause and Cure of Interior Wall/Ceiling Nail Pops, Drywall Gaps or Cracks
According to Carson Dunlop Associates, this cosmetic problem in homes in cold climates with roof trusses may result in significant cracks between interior walls and ceilings, or between interior walls and floors. The cause is upward bowing of the roof trusses to which the ceilings are attached.
[Click to enlarge any image]
As we also discuss both and CEILING FINISHES INTERIOR at WALL FINISHES INTERIOR, roof truss uplift is a well-understood cause of cracks at the wall/ceiling juncture at building walls located under the center (usually) of certain roof trusses.
Roof truss uplift occurs when the bottom chord of the truss is exposed to significantly different moisture or temperature conditions than the rest of the roof truss. For example if the bottom of the truss is buried in insulation while the remainder is in the open attic air, this condition can occur.
Photo at left: this is the type of separation crack that you may see at the ceiling-to-wall drywall joint over a center partition that runs at right angles to the bottom chord of rising roof trusses.
Builders avoid truss uplift cracking or ceiling nail pops by using special truss uplift clips to connect the ceiling and wall drywall while avoiding nailing or screwing the ceiling to the bottom of the trusses within 24" of the building walls. [See the roof truss uplift remedial action sketch just below.]
Why does truss uplift damage appear at interior partitions in the center of a building?
Because the truss ends are secured to building exterior walls - a location that resists outward thrust, as the truss bottom chord wants to expand along its length, the force pushes it upwards into the attic space.
Therefore roof truss uplift is most likely to be observed at the ceiling-wall juncture of central interior wall partitions that run at right angles to the direction of the roof trusses, or in other words, interior partitions that are parallel to the house front and rear eaves.
That's where truss uplift cracks may occur (typically in the center of the truss).
Builders avoid truss uplift cracking or ceiling nail pops by using special truss uplift clips to connect the ceiling and wall drywall that avoid nailing or screwing the ceiling to the bottom of the truss within 24" of the building walls where uplift may occur (typically in the center of the truss).
The drawings of roof truss uplift and corrective measures for truss uplift shown here are provided courtesy of Carson Dunlop Associates and appears in their Illustrated Home.
Green link shows where you are in this article series.
Frequently Asked Questions (FAQs)
No FAQs have been posted for this page. Try the search box below or CONTACT US by email if you cannot find the answer you need at InspectApedia.
Use the "Click to Show or Hide FAQs" link just above to see recently-posted questions, comments, replies, try the search box just below, or if you prefer, post a question or comment in the Comments box below and we will respond promptly.
Search the InspectApedia website
HTML Comment Box is loading comments...
Technical Reviewers & References