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Wood shingle roof, Metal roof-over, worn out (C) Daniel Friedman Re-roof with Wood Roof Shingles & Shakes

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.

InspectAPedia tolerates no conflicts of interest. We have no relationship with advertisers, products, or services discussed at this website.

Re roofing With Wood Shakes or Wood Shingles?

Wood shingle roof past end of life © D Friedman at InspectApedia.com 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?

Adapted/paraphrased with permission from Best Practices Guide to Residential Construction (Steve Bliss, J Wiley & Sons) , chapter on BEST ROOFING PRACTICES:

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 2-46: Wood Roof Shakes Installed over Spaced Sheathing (C) J Wiley, S Bliss

Figure 2-48 below. [Click any figure or table to see a larger, more detailed version.]

Figure 2-46: Wood Roof Shingle installation detail (C) J Wiley, S Bliss

Advice for Installing Wood Shingles or Shakes Over Existing Wood Shingles

Curled wood shingle roof - early failure © D Friedman at InspectApedia.com Our wood shingle roof photo at left raises some interesting questions about both the original wood shingle installation and now the question of roof replacement.

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 (Steve Bliss, J Wiley & Sons) .

Advice for Replacing Individual Lost or Damaged Wood Shakes or Shingles

Slate roof repair method for installing individfual slates without having to do a tear-off (C) Daniel FriedmanReader Question 6/23/14 Kevin P. said:

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?

Reply:

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.

 


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Reader Comments, Questions & Answers About The Article Above

Below you will find questions and answers previously posted on this page at its page bottom reader comment box.

Reader Q&A - also see RECOMMENDED ARTICLES & FAQs

On 2021-04-19 by Angela Waterford

Thanks for reminding me to not put building felt underneath the new singles since this may hinder them from drying. I'm thinking of installing roof overs over my existing roof shingles to preserve it since I live in an area that rains quite a lot. I hope I find a company that makes high quality roof overs soon.

On 2020-02-19 - by (mod) -

You'd need to add furring strips as nailers; but it'd be a far better and safer and longer-lived job to remove the existing asphalt shingles first.

On 2020-02-19 by Jeff

How do I put wooden shingles over asphalt shingles on a shed?

On 2018-12-08 - by (mod) -

No for several reasons. First I think if the states were not on a smooth surface they would be broken in a Flash. Second is that the structure of a roof designed for wood shingles which are much lighter than sleep may not be strong enough to carry the weight of a slate roof. So even if you take off the wood shingles you need to look at the structure of the roof that is the size and spacing of your rafters.

On 2018-12-07 by Peter Bennett

Can a slate roof be installed over wood cedar shingles?

On 2018-10-08 - by (mod) -

Brian

I don't feel confident that I can access your roof or structure by the text that we have. But I can give a general answer. In my opinion it would be a better Roofing job to strip off the old shingles. Nailing plywood sheathing atop the existing and most likely worn and damaged wood shingles or shakes gives an uneven mailing surface and makes a pine plywood roof decking questionable. You may also be adding more weight than the structure is designed to carry. A better installation would be to remove the shingles or shakes. You may be able to leave the furring strips to which those were nailed and put the plywood atop that.

On 2018-10-08 by Brian

I have a Decra metal shingle on a batten system over the original wood shake. Can the Decra be removed, the batten system and wood shingle left in place, and plywood or OSB sheathing applied over the batten system? Basically, I want to check if the wood shingles could be left in place so that sheathing and comp be applied.
Thanks for any help.

Question:

(June 23, 2014) Kevin P. said:
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?

Reply:

Kevin for better space and to allow an illustration I've moved your question and our reply to the bottom of the article shown above. Keep me posted on how your repair progresses. Use our CONTACT link to send me some sharp photos and I may be able to comment further.


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