Serious soft spot in house roof - What do I do? Need info ASAP!

I was blowing some pine shats off my roof yesterday with a leaf blower and stepped on a soft spot where the rood shingles caved in about an inch or so where my foot stepped. In looking at the underside of the roof from inside the attic it appears the problem area is about 2 feet wide and 4-5 feet long. just past the roof penetration of the kitchen vent which I assume is there the moisture is getting in. I was getting occasional leaks in the kitchen above the range hood when the rain was very heavy, but I assumed (apparently incorrectly) that this rain was rain being blown into the vent .
The rest of the roof appears to be fine and have had no problems with leaks.

My house was built in 1955 and the interior of the attic below the tar paper appears to be 2x4’s and the roofing shingles were apparently nailed directly to the boards roof as thousands of nails penetrate the interior of the attic boards.

I need to know

1: What is the best way to seal or protect the roof temporarily until I can get professionals in to look at it? I have a large blue tarp I could tie to the chimney, but making it fast to the roof might be an issue. Is fastening the tarp to cinder blocks or holding it down with bricks a viable strategy?

2: Is this a job I could do myself? I’m assuming I would have to remove a 10x10 section of roof to lay in all new boards and tar paper etc. but as the asphalt shingles are stacked form the apex like and interlocking puzzle I’m wondering if the job will require a while new course of shingles all the way to the apex of the roof.

Rain is in the offing so timely replies appreciated.

I think the most typical roof construction these days is rafters, then plywood, then tar paper, then shingles nailed through to the plywood. If your attic has what look like separate boards above the rafters, I’m going to guess with some uncertainty that they are 1X boards with tongue-in-groove joints between them.

I think anything you do that achieves two goals would be fine as a temporary fix. The first goal is to have seams running uphill only - that is, no joints that go downwards for the rain to follow. If you stuff tarp or, better, aluminum flashing (like aluminum foil but maybe a dozen or two times thicker) up under the downhill edges of shingles that are uphill from your problem, and also run the flashing up the sides of the vent and tape it there, I think you will satisfy this first goal. The second goal is to fasten things down well enough that they won’t blow away. There’s no reason bricks or other weights won’t do this, if they are heavy enough, but it is pretty scary to risk them falling off the roof, especially if people can get underneath them. If it were my roof, I’d nail around the area to hold the flashing down. For one thing, when the roof gets patched, nail holes are easy to patch or just ignore if they’re covered by new shingles. For another thing, any good repair is going to remove the wood around the rotted area anyway.

You can also go into your attic and wrap towels or other means around the spot water could enter, including around the vent pipe. While water could do a lot of damage if it isn’t noticed for some time, it isn’t going to melt your house instantly. If you put plastic sheeting under it, and tape that to your vent pipe so the water can only run into the towells, it should be OK.

I think they can patch areas without running new shingles all the way up to the ridge.

A tarp that is secured with ropes to your gutters for starters or screw them into the fascia board. You can put bricks down but you you know what’s going to happen when a strong wind hits it. I don’t understand your description of the shingles:but as the asphalt shingles are stacked form the apex like and interlocking puzzle I’m wondering if the job will require a while new course of shingles all the way to the apex of the roof.

If they are normal shingles then you can piece in new shingles without a problem. You pry up the old shingles, un-nail them and then nail in new shingles. Don’t skimp on the tar paper because it really makes a difference what you use. I used something called Mule Hide(?) and it was much tougher than regular tar paper (doesn’t tear as easily). Since you don’t have a contiguous flat surface this becomes more important. layer it like you would shingles to the old tar paper so water will flow properly.

If you’re about due for new shingles then this would be a good time to consider a complete tear-off and the addition of sheeting. I just went through this at my house. It’s a bitch to tear off of slats to get to a flat surface.

Re “interlocking” I meant that one shingle overlaps on top of another just like a normal roof shingle. I didn’t really see how I would remove one without removing a whole course of them but I’m probably misunderstanding the mechanics of how shingles can be replaced.

I think I’ll do the flashing nail down and seal the edges for now. I was concerned about nailing into the roof but if they are easily sealed it makes things simpler.

It looks like you have to do a whole course but you don’t. You pry 2 shingles above the shingle you’re replacing to get to the nails and slide out the bad one. You may only have to pry up the shingle above depending on how it was nailed. You’re suppose to nail just BELOW the glue line (which catches 2 shingles). If the nails are above the glue line than you only have to pry up the shingle above to get to it. Once you pull the nails from a shingle you can slide it out and slide in a new one. Use roofing tar to cover the old nail holes and also to reglue the shingles down. You’ll have to pull out enough shingles to get to the boards that need to be replaced. There is no reason why you can’t do this in an afternoon. Be forewarned, not all shingles are the same width. I just had to trim 1/4 inch off the length of replacement shingles because they weren’t an exact match.