# Rafter Baffle Install



## Nealtw (Jun 22, 2017)

The 22" ones should be fine. ,


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## oggy bleacher (May 3, 2011)

thanks for reply. of course I may not be able to find 22' wide baffles while the 14'' variety are plentiful. would a single line of 14'' baffles per rafter space work? 14'' actually matches the cuts I made for the soffit and ridge vents.


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## Nealtw (Jun 22, 2017)

oggy bleacher said:


> thanks for reply. of course I may not be able to find 22' wide baffles while the 14'' variety are plentiful. would a single line of 14'' baffles per rafter space work? 14'' actually matches the cuts I made for the soffit and ridge vents.


 Trusses are popular now so 22s should be available, maybe not the box stores but they would likely bring them in for you. Or do 2 of the 14s. 

You are always trying to get more on the intake than the high ones.


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## oggy bleacher (May 3, 2011)

I found the 22'' wide egg carton material variety. If the rafter area I'm working on wasn't so complicated by overlapping and uneven boards and scab braces then the best approach would probably be to hang a ledge for rigid foam boards and skip the baffles. Then the whole surface of the rafter void would be ventilated rather than half.


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## Nealtw (Jun 22, 2017)

oggy bleacher said:


> I found the 22'' wide egg carton material variety. If the rafter area I'm working on wasn't so complicated by overlapping and uneven boards and scab braces then the best approach would probably be to hang a ledge for rigid foam boards and skip the baffles. Then the whole surface of the rafter void would be ventilated rather than half.


 You should lower the ceiling or part of it to get insulation in there. 

See the blue line.


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## oggy bleacher (May 3, 2011)

I agree. I'm taking the current ceiling out completely section by section. It's just this 1/4'' plywood nailed to some 2x4 beams they rested on the tops of the knotty pine walls for the sole purpose of acting as a nailing surface for the plywood. 

After putting up this small amount of irritating fiberglass insulation I think I'm going to get some mineral wool insulation.


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## Nealtw (Jun 22, 2017)

oggy bleacher said:


> I agree. I'm taking the current ceiling out completely section by section. It's just this 1/4'' plywood nailed to some 2x4 beams they rested on the tops of the knotty pine walls for the sole purpose of acting as a nailing surface for the plywood.
> 
> After putting up this small amount of irritating fiberglass insulation I think I'm going to get some mineral wool insulation.


If you are taking the ceiling down, I would sister the rafters with 2x10s


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## oggy bleacher (May 3, 2011)

sister the rafters?...like put a 2x10 block between rafters? I'm not super savvy on some of the terminology. I attached a photo looking down the ceiling cavity. It looks like all the rafters were either reused or else the porch was shorter by half at some point in the past and they sistered on an extension. The vertical boards seem to be holding the horizontal beams level so they complicate how I attach a new ceiling.

I was going to leave the 2x4 beams that are horizontal because I can paint them and I'll have a place to mount a light and a fan. Structurally I'm not changing anything. I'll just end up with a ceiling that is ventilated and about 2 ft higher than before.


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## Nealtw (Jun 22, 2017)

oggy bleacher said:


> sister the rafters?...like put a 2x10 block between rafters? I'm not super savvy on some of the terminology. I attached a photo looking down the ceiling cavity. It looks like all the rafters were either reused or else the porch was shorter by half at some point in the past and they sistered on an extension. The vertical boards seem to be holding the horizontal beams level so they complicate how I attach a new ceiling.
> 
> I was going to leave the 2x4 beams that are horizontal because I can paint them and I'll have a place to mount a light and a fan. Structurally I'm not changing anything. I'll just end up with a ceiling that is ventilated and about 2 ft higher than before.


 To sister, nail another on the side of the original.
your rafters have crack and doomed to fail soon 

They need something nailed to the sides to make them strong. 2x8s or 2x10 would make them strong and give you room for insulation. 

If some one was to walk on the roof in that area, those rafters could completely fail.


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## oggy bleacher (May 3, 2011)

thanks for any advice on this. on the topic of bracing, it looks like every rafter has split at the old top plate location as the extension board was nailed too low. So, my plan once the ceiling is down is to jack up the rafter so it's back to the original orientation again and nail a 3' long scab over the split. There is not much weight above it so would that kind of repair work?

I wrote this before I saw your response. I agree, the rafters are split and need to be braced. But you recommend a 2x10 and not just another 2x4?


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## Nealtw (Jun 22, 2017)

oggy bleacher said:


> thanks for any advice on this. on the topic of bracing, it looks like every rafter has split at the old top plate location as the extension board was nailed too low. So, my plan once the ceiling is down is to jack up the rafter so it's back to the original orientation again and nail a 3' long scab over the split. There is not much weight above it so would that kind of repair work?
> 
> I wrote this before I saw your response. I agree, the rafters are split and need to be braced. But you recommend a 2x10 and not just another 2x4?


I would nail on full length if you can,a 2x4 would do it. I suggested bigger lumber so you can insulated properly. so you solve 2 problems with one fix.


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## oggy bleacher (May 3, 2011)

oh, I get it. the excess of the 2x10 acts as an extension to staple the insulation up. pretty smart. The one rafter I worked on just barely accommodated the insulation plus baffle to the point that I had to push the plywood up to screw it in place.

. I will look at this closer when I get the ceiling down. maybe a full length 2x8 or 2x10 sistered over that split in the rafters will give me an easier way to get drywall up.

thanks for the advice.


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## Nealtw (Jun 22, 2017)

oggy bleacher said:


> oh, I get it. the excess of the 2x10 acts as an extension to staple the insulation up. pretty smart. The one rafter I worked on just barely accommodated the insulation plus baffle to the point that I had to push the plywood up to screw it in place.
> 
> . I will look at this closer when I get the ceiling down. maybe a full length 2x8 or 2x10 sistered over that split in the rafters will give me an easier way to get drywall up.
> 
> thanks for the advice.


If you squeeze insulation and baffle in a 2x4 space, you either have crushed the baffle or have 2" of R value with the insulation in a 2x4 space That is hardly worth doing when you would like to get up to around 40 R


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## oggy bleacher (May 3, 2011)

agreed. making the cavity deeper with a 2x10 while bracing that split rafter is the way to go.


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## oggy bleacher (May 3, 2011)

After watching this video and reading the comments my plan is to try to sister a board using glue and bolts. And try to use a board all the way at least to the ledge that bears the load. This is just a porch but if its possible to get a board to span from load wall to load wall then I will do that. A short patch really is just dead weight that eliminates the split but doesnt bear any weight.


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## oggy bleacher (May 3, 2011)

After examining this framework closer i determined the 2x6 is underutilized as a Support for the sistered rafters so I added two supports between it and the furring strip i added for insulation. This fixed the two split rafters but I can forget about a second floor.
The vents arent going to help with heat. And there is no moisture in the Sonoran desert so insulation needs to be maximum. Cutting through the roof deck plus 2 layers of asphalt and tar was a real joy but if i had to do it again I would angle the sawzall blade to just cut the wood because the asphalt was brittle and breaks way easier than it cuts.

My original plan was to insulate with r13 f.g. batts but now the heat is really pouring down I am leaning toward r13 + unfaces r30 plus radiant barrier and battens and finally some kind of ceiling... at the same height as before but with about 15 inches of insulation up to the vent baffles. Closer to the eave there is only room for r13.

Finishing the ceiling above the joists but below the rafters looks too complicated/messy and i would be losing my chance to maximize to insulation while only gaining 10 inches in open space above the rafters which is just more space to heat and cool. The tradeoff makes no sense with summers getting hotter. 

Ultimately this is phase one in adding air conditioning to the room.


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## Nealtw (Jun 22, 2017)

Looks good, you will want a ceiling that is sealed, can you do away with the junction box.


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