Yesterday I inspected a house, that had a bat and board style roof instead of plywood sheeting. This house was built 50+ years ago. It has a composition shingle roof with several leaks. Can you put this type of roof on a bat and board roof? I don’t beleive you can, I wrote it up repair or replace with plywood or OSB sheeting. Any views on this?
Space planking is fine. It is actually better than plywood or OSB as it allows much better ventilation to the underside of the shingles. Typical for age. It there are leaks of course the shingles should be replaced/repaired. The planking is no problem and the existing shingles could be stripped with new shingles applied on existing decking.
i agree but on this roof some of the spaceing is more than 1" wide and the nail strip falls in that space and is leaking i dont believe this is the rite roof covering for this type of sheeting?
orr is it just a poor job of roofing
In that case they could whe replacing shingles fill the larger gaps with firring. Or they could place OSB or plywood over current planking. Personally I like plank spaced decking. But the spacing should not be more than quarter inch.
OK…you want my TAKE on it…
I called my brother who also is a roof contractor and asked him because for many years I have been taught that Roll Comp, Asphault Comp., Built Up require solid decking and I believe this is considered solid decking the way it looks in the picture…
Now just for fun I called him…my brother said the reason solid is required on Asphault is because of the placement of the nails to support the shingle itself…would be too hard to maintain the correct placement since many will not determine the proper way to lay the decking…so it would be impossible for a 2nd layer to ever be applied correctly since it would not show the exact location of the under decking to nail into correctly…Not to mention the requirement for FELT could make the install quite tricky.
Again…this is just to say WHY spaced decking is not allowed…put them together like in the picture and it becomes solid decking and fine.
also since 1 layer of 15LB felt on roofs 4:12 and 2 layers on 2:12 the underneath would not need to breathe like you would have on Wood Shingles…
Anyway…If I saw spaced decking and a asphault roof I would refer it to a roofing contractor…but again thats MY opinion and this looks SOLID to me…
Some may disagree, but my old mans’ house was built in approximately 1940,and the house was roofed with boards that were not squared off. The roofing shingles spanned the gaps and the attic ventilation did not exist. The roofing would last for 30-40 years. From 1951-1969, I do not remember that the roofing was replaced.
Of course, I was not an Inspector back then. ha. ha.
The lack of solid substrate underlayment, is not always the problem. Look further.
Marcel
Thanks Paul, that’s what I was looking for. The subject has been in much debate in my mind and with some of the people I have worked with in the past that are roofers. It seems half of them say this is no problem, and the other half say this is a problem. I wish I had better pictures, but this is not a soild roof sheeting. Some of the gaps are as much as 1in thick. It has come to my conclusion that I was right in my original assessment. I wrote it up as half liscened roofer evaluate and make reapairs as needed.
Would that be the same “half” licensed roofer who did the original work? 
Sorry.
Darn margaritas.
A good roofer would not have any problem with plank spaced roof decking. They do make chalk lines and can mark the nail line very easily.
A roof of this age has most certainly been reshingled over the years without the necessity of solid decking. Perhaps the shingles are old and the current installation was never installed correctly?
Am i missing something? The picture looks to me like a tongue and groove roof deck typical of 50s construction. Looks like the ridge has been cut back (or at least one side of it) for a ridge vent.
If thats what i’m seeing, i would rather have this roof deck than a plywood or particle board deck as the inevitable leaking near roof penetrations (over time) will not adversely affect the 1x as soon as it would the plywood / osb.
Adam, A Plus
I am with Raymond and Adam on this one that asphalt shingles on wood plank roof decks/sheathing is fine, as long as it’s not deteriorated and there are no large gaps between the planks. While contractors may be able to install asphalt shingles on spaced wood plank decks/sheathing, it’s not good practice and would not meet current construction standards.
Spaced wood plank decks/sheathing is permitted for wood shingles, with a few limitations/requirements (see IRC R905.7.1), but not for asphalt shingles. IRC 905.2.1 on sheathing for asphalt shingles requires that “Asphalt shingles shall be fastened to solidly sheathed decks”. Planks with significant gaps would not be “solid” … -(
JMO & 2-nickels … 
Almost all the old homes in my area have spaced planking that is usually 1/4" - 1/2" gap max. Planking spaced further apart on old house may be an indication that the roof was once wood shake.
Good point to keep in mind … 
Hi to all,
Would I write up asphalt shingles installed over board sheathing, NO WAY prior to the 1960’s there was no solid sheathing at all and all roofs were laid over boards.
I have been involved in many re-roofing projects over older board decking and as others have said you just need to repair any damaged boards (they frequently have split edges from old nailing) I would not report the roof as deficient due to this condition, we can’t start imposing modern IRC codes on home built prior to the code and before the advent of modern sheathing materials.
If the singles are not correctly nailed due to gaps between the boards then that is all I would report.
My own home in New England (built 1920ish) had practically unfinished baords as the roof decking, and some needed replacement, and some areas needed to be furred out. (the boards themselves were non-dimensional 1" thick and varried between 6’ an 12" wide)
Regards
Gerry
Tear off the existing roof sheathing because it isn’t plywood? Seems rather extreme. Do you have a roofing contractor license? If not, I wouldn’t ever say such a thing. “Recommend evaluation and repair by a licensed roofing contractor.”
Here you go guys, My place built around Circa 1890. No Venting in my attic until the “new” roof was installed Notice something…
I disagree with ya on this one mate. I may not report the condition as a defect that needs repair unless there were signs of problems, but I would at least report it as a concern. Spaced wood decking/sheathing with asphalt shingles was not common even for a 1960’s home. Also, materials have changed over the years, and applying a newer roofing system over an old deck that doesn’t meet current manufacturer’s and industry standards is not a good idea.
In addition, present day manufacturers of asphalt shingles require a solid wood deck for attachment, and application on older spaced wood decking could void the warranty (see this link for one example … http://www.gaf.com/Content/Documents/20222.pdf). That is exactly why the spaced wood decking on one house rehab project I was involved with got stripped off and replaced with plywood … just too much effort to fill in the gaps to meet the mfr requirements, and ya ended up with partially questionable existing deck areas after all that work.
Hmmm … I was pretty surprised by that comment from you since you are such a big fan of HI’s using the CodeCheck series as a field reference, and since an HI has little to reference besides an SOP and current industry standards (such as the IRC and NEC) which you often quote/reference yourself.
I would then assume you also wouldn’t report on the lack of GFCI receptacles in an old bathroom, or older framing with limited beam bearing or no hurricane/earthquake tie downs in risky areas (like FL) … all of which were acceptable at some time for older homes but wouldn’t meet current construction standards (and for good reason).
Sorry mate, couldn’t resist …
Rob,
I always advocte calling out any and all safety issues, this isn’t one, at best it is a performance issue.
Regards
Gerry
Inadequate anchors/strapping in an older home would likewise not be a safety issue, as it’s a building performance issue due to the excessive damage that could occur over time due to storms, but should be called out as a concern every time.
Incorrectly/inadequately nailed shingles (as a result of locating the attachment at planks) also wouldn’t fair to well in a storm. That’s a common problem/defect here along the northeast coast. Shingle that are not correctly/adequately nailed go flying in the first good storm.
Just a little surprised by your take on the spaced plank decking with asphalt shingles, as a client should be aware that the roofing may not perform well over time due to storms, may have a voided material warranty, and the client may have to spend a good amount of money to correctly replace the shingles in the future if they want it done right with a full warranty from the manufacturer. Maybe you just need some more time living in the hurricaine capital of the US down there in FL (duck … lol).
JMO & 2-nickels …
Very common in South Texas in the 1930s, 1940s, 1950s, 1960s, and 1970s.
I find it out here quite often on homes built in the 1950s, 1960s, and 1970s, as well. Perhaps it has something to do with the hot, dry climate?