Question? Just ask us!
Free Encyclopedia of Building & Environmental Inspection, Testing, Diagnosis, Repair
InspectAPedia ® Home
ROOFING INSPECTION & REPAIR
AMERICAN CEMWOOD ROOFING
BEST ROOFING PRACTICES
BUILT UP ROOFS
CATHEDRAL CEILING VENTILATION
CERTIFICATIONS for ROOFING CONTRACTORS
CHIMNEY FLASHING Mistakes & Leaks
COLD WEATHER ROOF TROUBLE
DECKS, ROOFTOP CONSTRUCTION
EPDM, RUBBER, PVC ROOFING
EXTRACTIVE BLEEDING on SHINGLES
FIRE RETARDANT PLYWOOD
FLASHING on BUILDINGS
FLAT ROOF MOISTURE & CONDENSATION
GREEENHOUSE / SOLARIUM ROOF LEAKS
HEAT TAPES & CABLES for ROOF ICE DAMS
ROOF ICE DAM LEAKS
MASONITE WOODRUF FIBERBOARD ROOFING
NOISE CONTROL for ROOFS
PLASTIC ROOFING TYPES
PVC, EPDM, RUBBER ROOFING
ROOF ARCHITECTURAL STYLES - PHOTO GUIDE
ROOF CLEANING RECOMMENDATIONS
ROOF COLOR RECOMMENDATIONS
ROOF INSPECTION SAFETY & LIMITS
ROOF LEAK DIAGNOSIS & REPAIR
ROOF NOISE TRANSMISSION
ROOF REPLACEMENT SNAFUs
ROOFING FELT UNDERLAYMENT REQUIREMENTS
ROOFING MATERIALS, Age, Types
SADDLE CONSTRUCTION at CHIMNEYS
SNOW GUARDS & SNOW BRAKES
STANDARDS for ROOFING
STRESS SKIN INSULATED PANELS
TEST LABS - ROOF SHINGLE
TREES & SHRUBS, TRIM OFF BUILDING
TRUSSES, FLOOR & ROOF
UNDERLAYMENT REQUIREMENTS on ROOFS
VENTILATION in BUILDINGS
WALK-ON ROOF SURFACES
WARRANTIES for ROOF SHINGLES
WORKMANSHIP & ROOF DAMAGE
Roof-over with wood shingles or shakes: this article discusses re-roofing over other materials using wood roof shingles and shakes. We describe installing wood shingles or shakes over asphalt shingles, or installing new wood shingles or shakes over existing wood shingles or shakes. We list manufacturers & product sources for wood shingle or shake roofing.
Green links show where you are. © Copyright 2015 InspectApedia.com, All Rights Reserved.
Our page top photo shows a wood shingle roof on the historic Mesier Homestead in Wappingers Falls, NY. Or wood roof photo at left illustrates a wood shingle roof that is past end of useful life. This roof needs replacement.
[Click to enlarge any image]
Can we roof-over this surface with new wood shingles or does the roof need to be stripped off?
Under some conditions, shakes and shingles can be installed over existing roofing, as follows:
Advice for Installing Wood Shingles or Shakes Over Existing Asphalt Shingles
If the existing asphalt shingles are not overly cupped or deteriorated, split or rough-sawn shakes can be installed over the shingles using interlaid strips of felt, as described above. Installing wood shingles over asphalt, however, requires a ventilating underlayment such as Cedar Breather or a system of battens (as shown in Figure 2-47 and Figure 2-48).
Figure 2-48 below. [Click any figure or table to see a larger, more detailed version.]
Advice for Installing Wood Shingles or Shakes Over Existing Wood Shingles
The shingles do not look worn compared with our worn-out wood shingle photo shown earlier in this article. But the shingles are badly curled and many are splitting, risking leaks. The roof seems to be failing earlier than one might have expected.
We recommend diagnosing the cause of this problem before re-roofing. Is this wood shingle curling and splitting due to:
A second question is whether or not it would be reasonable to roof-over this existing surface. Without diagnosing the ventilation question first one might hesitate in any case to roof over this surface, but roofing over badly curled roof shingles on an existing roof is asking for trouble. The new roof may itself be unable to lie flat and the uneven underlying surface may contribute to early splits in the new wood shingles or shakes.
If the shingles are not badly curled or deteriorated, they can form an adequate surface for new shingles or shakes.
Watch out: Do not place building felt under the new shingles as that could inhibit drying, but if there is a high risk of decay (moist environment, low slope, overhanging trees), a layer of Cedar Breather is recommended. Shakes should be installed in the normal fashion with interlaid felt. Use nails long enough to penetrate the sheathing.
Advice for Installing Wood Shingles or Shakes Over Existing Shakes
In most cases, these will need to be removed before re roofing, as the surface is too irregular, and nailing through the shakes into solid sheathing is impractical.
More Information about Wood Shingle or Shake Roofing Materials, Methods, Standards
-- Adapted with permission from Best Practices Guide to Residential Construction.
Advice for Replacing Individual Lost or Damaged Wood Shakes or Shingles
Lets say that you have a condition in which a storm event has resulted in a handful of broken and/or partially displaced wood shakes on the roof.
What would be the best strategy for replacement of those individual shakes?
Can they easily be spot replaced, or would it require a sequence of events, including a large area of removed shakes either above or below the damaged shake?
Kevin, an experienced roofer who is familiar with wood shake roofs can replace or repair missing or loose shakes in spots without removing large areas of materials.
S/he might have to work from a ridge-hooked and padded ladder on some fragile roofs that can't be walked-on without risking further damage, but key in any event is the use of repair methods similar to that for repairing slates - another non-flexible roof material that doesn't allow you to just "lift up" an upper shingle course to nail a lower shingle in place.
You'll see that using a slate hook or even a simple strip of copper (see our sketch at above left) can allow us to hold new slates (or shakes) in place when just a few spots need repair - a much less invasive and much less costly approach.
See SLATE ROOF REPAIRS for examples of these individual shake or slate replacement methods.
Continue reading at WOOD ROOF COATINGS & FIRE RATINGS or select a topic from the More Reading links shown below.
Suggested citation for this web page
Green link shows where you are in this article series.
Frequently Asked Questions (FAQs) about re-roofing with wood shingles or shakes
Questions & answers or comments about roofing over an existing roof using wood shingles or shakes.
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