Friday, November 1, 2013

Porch Repair

This has been one of the biggest projects ever, but one of the most fun. I had help from my grandpa and an uncle, plus consultation with another uncle for this project. The porch roof has been leaking forever. The asphalt shingles were completely disintegrated. There was a big sag in the ridge. I knew there were going to be issues. Since the new slate roof is getting installed soon, I figured this was a project I could tackle myself to save a few thousand dollars. 

I started by tearing off the existing asphalt shingles. The original slate had already been removed from the porch roof, even though it still exists under the rest of the roof, and there were 2 layers of asphalt shingles over the porch, indicating someone had already attempted to repair some issues before. I stripped the asphalt off, no pieces larger than 3 sq inches. It just disintegrated and came off in tiny little bits. A lot of the decking was rotted, which I already knew would be the case. I decided that I'd just go ahead and replace ALL of it. At least half of the beadboard on the eave was rotten, which I had already known from when I replaced the cedar shake on the front. What I was more interested in finding out was WHY there was a big sag in the ridge. 

Once the tearoff was done, the source of the sag was obvious, a crack in the ridge board along a knot in the wood. I originally thought we'd have to cut the rafters away from the ridge board and replace it. I had a new one custom milled to the old wood dimensions but 2x8 instead of the original 2x6. Then I consulted with my uncle and learned of a much easier way to deal with it: put the new 2x8 underneath the original cracked ridge board and force it up, thereby straightening the cracked/sagging 2x6.

To do this, we had to support the porch while we worked. I placed two column jacks on the porch, lined up with a 2x8 that is directly below the cracked ridge, right on the top side of the tongue and groove porch ceiling boards. We had to make sure we had these column jacks directly under that 2x8 since that's what we'd be using to jack up the sag. Then we had to make sure that these column jacks were also sitting on the porch floor right on top of the joists that ran beneath, to transfer the load to a bearing area.

Once everything was properly placed, we tore off the 1x8 decking along the ridge so that I could climb inside. We sandwiched metal brackets along each side of the cracked board so that the new one could slide in underneath it and would not flip sideways while jacking. Then, pinning one end of the new 2x8 to the wall of the house, underneath the cracked board, we jacked up the other end with a bottle jack, about 4 inches to force the cracked board straight. Once it was seated along the bottom of the cracked beam, all the way across, and everything was straight again, we tied the two together with structural ties. Then installed joist hangers and other supports to make sure neither end will ever sink down.

After that milestone, I tore all the decking off of the north half of the porch roof. I had to leave the beadboard up temporarily as it was holding up the large fascia board. I removed all the old rusty nails from the rafters and cleaned up all the asphalt, slate chunks, dirt, birds nests, roofing nails, etc from the top side of the porch ceiling boards where it had collected for 100 years. I then reinforced EVERYTHING with joist hangers since the original nails that were used back then are getting rusty and disintegrated and can't be relied upon anymore.

After the teardown, it was obvious that some rafters would need to be replaced or sistered with new. Out of the 5 rafters on the north side, 3 had so much rot that it was best to just replace them, then I sistered one all the way, top to bottom, and sistered a 3 foot section at the bottom of the final one. After we had jacked up the ridge, a couple of the rafters had pulled away from the ridge so replacing the rafters also solved that problem. All the rafters were secured to the ridge with rafter ties or angled brackets. And 3" deck screws were added all over to tie things together that were originally nailed.

Once everything was structurally sound, the deck replacement began. There was no way I'd use plywood on my house (especially under a slate roof), so I bought all brand new 1x8 pine decking and beadboard. Rather than nailing it, I chose to screw the boards down with 2.5" deck screws, 2 per board per rafter. I also left a small (about 1/8") gap between each board to allow for expansion and contraction of the wood. 

Originally, almost all the beadboard (which is the only thing holding up that big thick fascia board), only came in to the first rafter. Over time, the weight of that large fascia board, the slate on top of it eave, and the lack of support, causes the eaves to sag down. It's a common problem in this city where apparently no builder figured out how stupid this was. So it is common here for roofers to have to jack up these eaves and replace some of these short beadboards with longer ones that go in at least a couple rafters. So when I replaced the beadboard, I used much longer pieces.

Then, I basically repeated that entire process for the south side. Plus, the end of the south side had always been sagging. At one point, someone attempted to fix this by sistering in some 2x4s but they were not level and only reinforced the drooping. I tore all that out and started over, making sure to level it and support it all with rafter ties. Also, the top of the fascia board on this side, a thick 2x8, was rotted. Removing it entirely and having one custom milled to those dimensions and reinstalling would have been a huge project. Since it was only rotted about an inch deep at the top, for a few feet in length, I just cut out the rotted section and glued and screwed a piece in that section (taken from a good portion of one of the removed rafters, so it was old growth and the correct thickness). Once the seam is puttied and it's all painted, it won't be visible.

This was a large job. It broke down something like this:
  • 1 day roof tear off and cleanup
  • 1 day pulling nails from deck and staring at cracked ridge, brainstorming
  • 1 day jacking cracked ridge and tying in new board
  • 1 day deck tear off (north side) and clean up
  • 1 day replacing and sistering rafters (north side)
  • 1 day installing new deck and beadboard (north side)
  • 1 day deck tear off (south side) and cleanup
  • 1 day replacing and sistering rafters (south side)
  • 1 day installing new deck and beadboard (south side)
  • 1 day misc


  1. Nice! Isn't it a great feeling fixing that sag? Love to see things done right, instead of fast as possible. It's gonna be so nice with that slate.

  2. That was an impressive crack at the knot in the ridge board. And that is an impressive repair. You porch is going look incredible and last a long time.

  3. Awesome! So what's going over the decking between now and when the slate goes on?

    1. I have a tarp covering it. The slate roofers have started the tear off. They are doing my entire roof in Grace Ice & Water Shield. As they tear off a section at a time, they cover it with the Grace which is totally waterproof and it can be left like that until the slate project is done. So as soon as they are done with the tear off of the front half of the roof (which falls onto the porch roof), they can cover the porch roof in the Grace.

  4. Well done, you! I'm glad for the slideshow; it helps me follow what went on. Ye gods, that rot was awful.

    Re: the spaces between the decking boards, I've heard that with slate, that is absolutely necessary. Wish I could remember why . . .

  5. Thanks. I think the spacing is necessary more for expansion and contraction of the wood. I think I read that in can buckle if you don't put the spaces in. It also probably would help with ventilation, with the slate, but since I put Grace Ice and Water Shield on the whole roof, there is no ventilation through those little gaps now, which is why I'm putting a ridge vent on. I can't imagine how hot it would get in that space with that ice guard (which is basically a rubber sheet) over the whole thing and no ventilation.

  6. What type of slate is being installed?

    1. It is brand new Vermont slate from Greenstone Slate. 16" tall x random widths. Historic color blend of green, grey, black, and purple.