Conference 7.286::home_work

    I don't have any suggestions regarding Nashua area roofers but we're
    having ours stripped and reshingled also.
    
    I do have a question though.  A guy came over to look at the roof
    this morning and told my wife that if there are currently spaced
    boards underneath they'll have to be removed and replaced with plywood.
    Something about a new law.  Has anyone out there heard of this?
    
    I replaced the porch roof last summer and the underlayment currently
    there has spaced boards.  Real 1" X 6" stuff.  I would think this
    is much stronger material compared to 1/2 or 3/4 plywood.  Having
    to replace this with plywood would obviously add a substantial cost 
    to our 2800 square foot area!
                                             
    					Steve

    Spaced boards? Hmmm .. dunno. A call to Town Hall should provide
    an answer to that. Did the contractor imply that the boards would
    have to be replaced only if they stripped the old asphalt off? I
    have plywood on my. Easy enough to tell where ice dams have built
    up. Interior portion of the plywood along the edges of the roof
    tend to delaminate over time from water.
    
    Paul

    Sounds funny. The only problem I could see is if when nailing
    down the new roof that you happen to hit the space between the
    boards. I reroofed my porch several years ago. It had spaced
    boards. I put down quarter inch plywood over them, then put down
    the new roofing. 
    
    On an addition I put on I put down a 2 inch board along the edge
    before I put down the rest of the plywood. If I have a problem
    with rot on the edge, all I have to do is replace the edge board.
    
    dave

    re .0
    Give Fred Noel of Noel Construction a call.  I've seen his work
    and he's very good.  I have him do all my major work.
    
    Steve
    

    Re: .3  Concerning spaced boards
    
    You're right in regard to the theory of putting the plywood over 
    the spaced boards.  My wife mistakenly thought he said something
    about it being a law. 
    
    I spoke to the contractor about his reasoning for the plywood. 
    He said that shingles were of different size way back when the spaced
    boards were put down.  He said that there would be times that they
    would hit this space and they'd have to make adjustments.  He also
    said the finished product with the 1/4 inch covering would be much
    better quality.  I agreed.  
    
    Now I have a couple of questions.  He said that they would use 1/4"
    esponite (grabs the nail better?).  Is this a cheap way out for him?
    And is it worth the extra grand (96 - 4X8 sheets) to have this done?
       
    					Steve

    Personally I don't like esponite (I think the spellings wrong),
    I used it on the walls of an addition and found it didn't have
    the holding power of plywood, but its cheap. You could try 
    mohoginy_lawn (spellings definately not correct) plywood. Its
    about 1/4 inch thick. Last time I got any , two years ago it
    was about $10.00 a sheet. 
    
    dave

    Particle board is made up of sawdust and glue. Its very heavy and
    hard to put a nail in. For buildings its usually used for subflooring
    before putting down tiles or carpets.
    
    espnite is made up of wood shavings , like from a plainer, and glue.
    Its a little lighter then plywood, easier to nail through. Usually
    used as a plywood replacement on the outside walls of buildings.
                             
    I don't rate either one good if it gets wet.
    
    
    dave

    Both materials are tough on saw blades...
    
    -Scott
    

    If you have spaces between the boards (say, greater than 1/2") 
    then you probably need to put something over them to give support
    to the asphalt.  If the boards are laid more or less tightly
    together and are more or less smooth, then I'd forget it.  I've
    got to do something like you're talking about on my roof when
    I reshingle, because it's rought-sawn slabs (bark on the edges)
    with really sizable gaps.  It's from the days of wooden shingles
    when spaces didn't matter, but asphalt requires a bit better
    surface.  1/4" plywood should do it.  
    
    Steve

	Getting back to the topic of this note: can anyone recommend
	a roofer in the Nashua area?

	I need to add ventilation to my roof, probably a ridge vent.

	Also, if you're interested in installing a ridge vent on my
	house in exchange for $$$, let me know -- a few hours on a
	weekend or two, perhaps.  (Ridge is about 18' up, two sections
	of vent, about 50' long total.)

	Regards, Robert.

    I'm planning to reroof an old house that was last done before plywood
    was invented.  I don't expect the rafters to be in the "right" place
    anyway for plywood, so I plan to use 1" X 10" unplaned pine.  The
    local sawmill also carries shiplap and I was wondering if this would
    be better on a roof.  Shiplap, in case you don't know, looks like
    this:
                           _________________   
    			__|               __| 
                       |__________________|                   
                                            
    

    I recommend using plywood, even if you have to cut it.  You'll
    have less chance of leaking.
    Shiplap is ok for the walls, but I wouldn't use it for a roof.
    It won't be tight enough to keep water out.
    
    Remember that you can get plywood in longer than 8' sheets if it
    will help.

    Use regular boards and save a few bucks - you don't need shiplap.  
    And you don't need plywood.  I think boards are much better for
    a roof, because they give any condensation that happens to get under
    the shingles a way to escape.  Plywood, because of the glue, is
    waterproof and will rot and/or delaminate.  I've re-roofed two old 
    houses with roughsawn 1x10 pine from the local sawmill, and it 
    works fine.  The shingles, not the roof deck, are supposed to keep
    the water out.  

    
    Plywood may be easier, but the pine will last longer.
    
    I've been reroofing a barn/garage, and I can tell you that the tongue
    and groove pine boards on the roof (which are very old), held up *much*
    better than the plywood (which is much newer).  I replaced most of the
    plywood, and very little of the pine. Plywood delaminates if it is
    exposed to too much water (even exterior grade).  If you can afford it,
    I think the shiplap is better.
    
    Don't count on either plywood or the shiplap to seal out the leaks.
    The shingles and tar paper (or whatever roofing material you use)
    should (better!) seal out the water.
    
    -tm
    

    While we're on the subject, I can't remember whether I used rough
    sawn or planed one side last time.  Is it worth it spending the
    extra for planed to get a smoother surface under the tarpaper?
    
    

    Planed or not...
    I think it depends in part on how good the sawmill is.  I wouldn't
    worry about it at all as far as smoothness under the shingles is
    concerned.  Planing probably would be a benefit if the sawmill can't
    saw boards the same thickness.  In that case, getting one side planed
    so the boards are all the same thickness might help.  Even a good
    sawmill will have some variation in roughsawn thickness.  Out of
    a couple thousand board feet from Parlee lumber in Littleton, I
    found only a couple that were enough "off" to be a problem, and
    it generally turned out the house was off enough so the extra thickness
    was handy to have someplace else on the roof.

    
    RE .6  "Luan" is the proper spelling, I believe.
    
    					Frank

    RE .-1
    
    Try  LAUAN.

    Just another example of "make sure you ask all the right questions when
    you're having a house built".
    
    My father in-law said to make sure that they use 3/4" plywood on the
    roof.  Well the framer is using 1/2" and all 50-70 sheets of it are
    already up laying on the ceiling joists ready to be nailed down. 
    
    I was all set to make the change this morning even if it meant that I'd 
    have to take the day off and lug plywood but the builder talked me out of 
    it this morning with the following argument:
    
    	- time is real tight with my rate lock (17-Oct) and they have to 
    	  take the time to lug the 1/2" off the roof, deliver the 3/4" and 
    	  lug it up to the roof 
    
    	- I'd have to pay for the difference and the additional labor.  The
          framers were ready to nail down the sheathing first thing this
    	  morning so time would be wasted.                  
    
    	- the roof joist are 16" OC and everyone uses 1/2" roof sheathing. 
    	  If they were 24" OC I would definitely need 3/4" but "we" make it
    	  16" OC so you won't have any problems.
    	                             
    	- you'd be foolish to waste your money on that, spend it on
    	  something else in the house
    
    	- "you think someone will look at that roof in 10 years and say
    	  "that's 1/2" sheathing up there" ?"
    
    I think he's right but I'd feel better about the house if I had at
    least 5/8" plywood on the roof.  If I had asked several weeks prior I 
    would have not hesitated and said use at least 5/8".
                                      
    So, talk to people who have been around and ask the right questions!
    
    Bill
    
                                      

>    My father in-law said to make sure that they use 3/4" plywood on the
>    roof.  Well the framer is using 1/2" and all 50-70 sheets of it are

	    In laws!  Is your FinL a carpenter?  Even if he is, I agree with
	your builder.  There is no justifiable reason to waste the time and
	money required to replace those 1/2" sheets with 3/4".  The 1/2" may
	sag slightly after a few years but it wont be enough to notice.  Take
	the $200 (not including labor) you'll save and give your FinL a one
	way ticket to where ever it will take him!
	   BTW (nit picking), rafters are the sloped supports for the roof.
	joists are the horizontal supports for the floors and/or ceilings.

					Tim

    	The 1/2" should be fine. It's more important to make sure you have
    adequate ventilation. If you don't already have one, spend the extra on
    getting ridge vent and make sure there are plenty of soffit vents.
    
    	Had you thought of this sooner in the process, the extra cost would
    not have been that much. At this point, I'd have to agree with the
    builder. Spend the money else where.
    
    	Ray

    I agree with the 1/2 inch but only if the rafters are 16 inces on
    center. If they are 24 inches(raters or trusses) use 3/4 and H clips.
     
    Sylvain

    Better built homes use 5/8. What a difference in the stiffness of the
    roof. This means minimum sag. The 1/2 ply (really 11/32) is not what
    is used to be.
    
    					/Dave
    

	My roofer bid (and used) 3/8" plywood, but instead of tearing off
	the whole roof, he kept the original loosely spaced planks on the
	roof.  The roofer who bid using 3/4" plywood wanted to do a complete
	tear down to the rafters, and while it would of been nice, his
	big was $3,500 more :-(

    I recently went to a structural engineer for some analysis on my
    new house.  One of the things he checked was plywood roof sheathing.
    1/2 inch plywood is good for up to 40 psf with 24" o.c. rafters. 
    5/8 is good for up to 50 psf.  The design load in Mass. is 35 psf.
    So structurally 1/2" is fine.  I would be concerned about bowing
    with the 1/2" though (at least if using 24" o.c. rafters).

    re .23  You mean 1/2 ply (really 15/32).  3/8 is really 11/32.  Right?