# Adding new roof over old to change pitch a little



## Nealtw (Jun 22, 2017)

So every 4 ft the rafter sits on top of the old rafter.
for the ones between you would need to add a block inside on top of the wall to support them.


Or cut out sheeting so the block can be added.


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## RobV4397 (Jul 11, 2017)

I can't cut into the sheathing of the old roof. It is a cathedral ceiling and I am worried about air leaks. Can I attach the blocks with simpson angle brackets screwed into the old rafter through the old sheathing? The blocks would be very small. Most rafters would be just over 13' long and rise only 6 inches at the ridge. One side does not end at the ridge but ties into the main part of the house and a 9 pitch roof.


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## Nealtw (Jun 22, 2017)

In that post I was talking about the lower end, I think you can just add a soul plate fro the rafters to land. At the top you have a little arrow up there, where that taper is 1 1/2" thick draw a 2x6 on flat there. So you shorten your rafter 1 1/2" measuring at 90* from the cut side of that taper.


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## RobV4397 (Jul 11, 2017)

I don't understand.


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## Nealtw (Jun 22, 2017)

RobV4397 said:


> I don't understand.


 So you are looking for how the land rafters on the roof when the rafters do not land on the other rafters?
Lay a 2x6 flat on the upper roof horizontally for the new rafters to land on.


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## craig11152 (Jun 20, 2015)

What about dropping a new rafter in between, then you are 12" OC and every other rafter sits on top of an original ?


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## Nealtw (Jun 22, 2017)

See the 2x6 that is not stained, under the top of the rafters.


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## RobV4397 (Jul 11, 2017)

Nealtw said:


> So every 4 ft the rafter sits on top of the old rafter.
> for the ones between you would need to add a block inside on top of the wall to support them.
> 
> 
> Or cut out sheeting so the block can be added.


I forgot, I'm cutting the ends of the old roof off so I may be able to get in there and add blocks to support the new rafters. Like you pointed out every 4 ft the rafters would line up. But adding the soul plate would raise up the bottom end 1 1/2 in. That might be best for my cut and cobble insulation install. I wanted to put 6 in of foam but was stumped on how to handle pulling that off with a 2x6 and still having space for venting.

One six foot section joins with the other roof line. Thanks for the video to show how that 2x6 is positioned flat at the top. Those rafters are going to be over 23 ft long. Do I build vertical supports along that? I'll have to do something because my 2x6's are only 16 ft long.

Also the 17 ft of roof that meets at a ridge with the other identical side of the great room. Should I design it with a ridge board or beam and I want it about 6 inches higher to make it 4:12. Should I just put a 2x12 as the ridge board?


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## Nealtw (Jun 22, 2017)

RobV4397 said:


> I forgot, I'm cutting the ends of the old roof off so I may be able to get in there and add blocks to support the new rafters. Like you pointed out every 4 ft the rafters would line up. But adding the soul plate would raise up the bottom end 1 1/2 in. That might be best for my cut and cobble insulation install. I wanted to put 6 in of foam but was stumped on how to handle pulling that off with a 2x6 and still having space for venting.
> 
> One six foot section joins with the other roof line. Thanks for the video to show how that 2x6 is positioned flat at the top. Those rafters are going to be over 23 ft long. Do I build vertical supports along that? I'll have to do something because my 2x6's are only 16 ft long.
> 
> Also the 17 ft of roof that meets at a ridge with the other identical side of the great room. Should I design it with a ridge board or beam and I want it about 6 inches higher to make it 4:12. Should I just put a 2x12 as the ridge board?


1. So at the bottom cut the tails and remove a little more sheeting to see the top of wall and supply some venting to the lower roof.
Add 2 2x4s on flat to the top of the walls to add 3" and closer match the height of the rafters. Cut a birds mouth in the rafters landing on the wall and maybe a slightly different cut to fit on top of the old rafters.


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## Nealtw (Jun 22, 2017)

2. The ridge, remove some sheeting on both sides of the peak to allow venting at the top. Adding a 2x10 or 2x12 on edge for a ridge board will work and can be tied in with some blocks nailed to it and something in the old roof.


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## Nealtw (Jun 22, 2017)

3. The span of 23 ft is to far. Cut thur the sheeting and built a wall above the wall of the blue house, so the studs sit on the lower wall or a plate sitting on the rafters below.
They extend thru the old roof with a double plate on top to supports the join in the rafters.


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## RobV4397 (Jul 11, 2017)

Nealtw said:


> 3. The span of 23 ft is to far. Cut thur the sheeting and built a wall above the wall of the blue house, so the studs sit on the lower wall or a plate sitting on the rafters below.
> They extend thru the old roof with a double plate on top to supports the join in the rafters.


I followed you on everything but I am really, really trying to keep the old roof intact as a second roof. I was thinking I could build up from that wall like you said but only to support the old roof. Then I could just build something to support the new rafters right above.
I explored up in that crawl space this morning. The original construction had the ridge beam extend all the way across. Here is a photo from 1968.


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## RobV4397 (Jul 11, 2017)

This is what that section looks like now.


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## RobV4397 (Jul 11, 2017)

This is what it would look like if you opened up the wall. The ridge board is still there and there is a vertical support about 1 1/2 ft back from that with a 2x4 running horizontally under the other rafters. 
Should I extend the new ridge board all the way across and build off that existing support or should I build up the wall like you said earlier Nealtw? Again I would really like to keep that original roof line intact. Thanks!


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## RobV4397 (Jul 11, 2017)

So this drawing is the work in progress. Extend the new ridge board all the way across and copy original support? I guess I could come through the old roof and just ice and water shield the openings. Could I just come up on either side of this 6 ft wide roof with 2x4 and run a support beam across to support the new roof? Then I would only have two cuts in the old roof.


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## Nealtw (Jun 22, 2017)

RobV4397 said:


> So this drawing is the work in progress. Extend the new ridge board all the way across and copy original support? I guess I could come through the old roof and just ice and water shield the openings. Could I just come up on either side of this 6 ft wide roof with 2x4 and run a support beam across to support the new roof? Then I would only have two cuts in the old roof.


As long as you can support the join in that long set of rafters to the ground.


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## RobV4397 (Jul 11, 2017)

Nealtw said:


> As long as you can support the join in that long set of rafters to the ground.


I have followed all of your recommendations so far on this roof. I've built a new top rail on both sides and I'm inside that small attic space getting it ready for a new wall to pop up through the old roof to support the long run of rafters. 

The concern I have now is there are no ceiling rafters holding the walls from bulging out. That is a large room (25'x 16') with only collar ties. The good thing is my wife wanted exposed wood beams and wood plank ceiling anyway. I was planning on removing all the sheetrock and pink insulation and having it spray foamed before I cover the rafters with nice wood boards.

Question: What are my options for beams to just hold the walls in place and not to support weight?

Can I go the whole 25' or should I drop a support down from the peak? Since the room is 16' wide I was thinking of four beams.


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## Nealtw (Jun 22, 2017)

RobV4397 said:


> I have followed all of your recommendations so far on this roof. I've built a new top rail on both sides and I'm inside that small attic space getting it ready for a new wall to pop up through the old roof to support the long run of rafters.
> 
> The concern I have now is there are no ceiling rafters holding the walls from bulging out. That is a large room (25'x 16') with only collar ties. The good thing is my wife wanted exposed wood beams and wood plank ceiling anyway. I was planning on removing all the sheetrock and pink insulation and having it spray foamed before I cover the rafters with nice wood boards.
> 
> ...


 It's been a while and it's early, which wall are you worried about moving. Is you support wall going up off the old house wall, will the ceiling still be in the house.


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## RobV4397 (Jul 11, 2017)

I am worried about the walls being pushed out because I only have collar ties. Need to tie the walls together with beams before I build a new 4:12 roof over the old 3:12 roof. I don't know much about beams and I want to know how to construct 4 beams over a 25' span.
Since they are not supporting weight can I use 2x4 and cover with the fake foam beam products out there or do I have to use 2x6?


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