Best way to retro flash roof against wood siding wall?

I had a contractor build a shed roof on the back side of my carport that extended over and attached to the house. The part of the house that it is attached to is wood lap siding. When he shingled the new roof he just used roofing caulk where the shingles meet the wall … no flashing of any kind. I’m afraid that with time that rain is going to find its way between the roof and the wall and cause wood rot. What is the best way to ensure no problems with this situation short of tearing the siding and/or shingles off and step flashing behind the siding like you would do if you were building a new house?

The only way is to cut a groove in the siding and flash the roof wall intersection. Or pull the nails out of the closest layer of siding and slip the flashing up under it, and hopefully under the moisture barrier.

imo and that is all it is. My opinion.

Do you also need one of these?

And it could be code.

**R703.1 **General. Exterior walls shall provide the building with a weather-resistant exterior wall envelope. The exterior wall envelope shall include flashing as described in Section R703.8 The exterior wall envelope shall be designed and constructed in such a manner that prevents the accumulation of water within the wall assembly by providing a water-resistive barrier behind the exterior veneer as required by Section R703.2 and a means of draining water that enters the assembly to the exterior.
R703.8. Flashing. Approved corrosion-resistive flashing shall be applied shingle-fashion in such a manner to prevent entry of water into the wall cavity or penetration of water to the building structural framing components. The flashing shall extend to the surface of the exterior wall finish. Approved corrosion-resistant flashings shall be installed at all of the following locations:
6. At wall and roof intersections.
R901.1 Scope. The provisions of this chapter shall govern the design, materials, construction and quality of roof assemblies.
R903.2 Flashing. Flashing shall be installed in a manor that prevents moisture entering the wall and roof through joints in copings, through moisture permeable materials, and at intersections with parapet walls and other penetrations through the roof plane.
R903.2.1 Locations. Flashing shall be installed at wall and roof intersections

Holy smokes, that is exactly what I need … I wanted to get this corrected before if installed new gutters and I couldn’t figure out how to keep the water from getting between the wall and the end of the gutter.


Carl is right-- roof to wall flashing needs to be installed if the missing flashing is along the top edge of the roof (flashing running parallel to the wall and top edge of roof)… which is what it sounds to be.

If there is any sloped plane of roof meeting a wall, then step flashing would need to be installed.

The shed roof does have some slope and the lap siding on the wall is 4". Again, color me uneducated about these kinds of things (which is true), but I’m having a difficult time of seeing how to retro flash where the roof meets the wall in my application. Do you have any pictures of something similar?


Can you post a picture of the area you are talking about?

Is it above where the kickout goes?

If so it needs to be cut where there is clearance between it and the roof so water can not wick its way up.

And that really goes for other places where the siding comes to close to the roof,concrete,dirt.

I am sure there is an inspector that belongs to this organization that could come out and inspect your house.

Photo attached.

Yes, it is above the kickout.

How do I locate the closest member of this organization to me? I have actually considered having an inspector come out before but only wanted to hire one who had considerable building experience and really knows what the heck he is doing. I really can’t afford (financially, emotionally and otherwise) to have any more jake legs working on my house, or guys who know how to do things right but don’t really care.

House shed roof 4.jpg

Just below the top left corner of the website. Inspector locator!


Please do not take this the wrong way, and I do not mean any disrespect.

In the future, hire a licensed and qualified guy to do this type of work.

I know that they are expensive and everyone is looking for a “deal”, but, when it comes to your house, the only “deal” is to have the job done correctly by a person who knows how to do it properly.

Decker’s Law:

Any home repair, improvement or addition will cost $X to do (properly).

You can choose to pay $X up front and have the job done right (the first time) or you can pay $X - Y and get a lousy job.

Sure, in may look like a good deal, but you will, in the long run, wind up paying $ (X-Y) + ZZZ to band-aid the fix over the years, and that does not even account for inflation and aggrevation and all the other damage that the original lousy job sill wind up costing you.

So: Pay $X up front, or pay X + ZZZ + aggrevation + extra damage + the rate of inflation + having your wife yell at you for being such a cheapskate + have all your neighbors having to look at the eyesore.

Your choice.

You (ALWAYS) get what you pay for.

Hope this helps;

Instead of hiring a home inspector, have a roofing contractor go out there and inspect the roof. Have this **experienced **roofer write up a bid for repairs that are needed and go from there. That is a crap job… siding needs to be trimmed up and proper step flashing needs to be installed. (as well as kick out flashing). From there, you can either take the original roofer to court, file with your state’s contactors board, have the new roofer make the repairs and submit a bill to the original roofer, or ??
Just the way I would go about it.

No offense taken. Believe you me, I am totally on board with only hiring the most qualified person available in the future. Yes, we were trying to save money with the guy we hired. That said, however, he did come with recommendations and was the father of a friend. As it turned out, it was a big mistake and we fired him part way through our remodel. All of this said, it is very difficult to find good craftsmen in our area and when you can find one you have to wait a long time to get them on your job … they can also sometimes be ridiculously expensive, as well as never seem to be in a hurry to finish (work one day, take one day off). And, almost everyone works on cost plus around here, so there is no incentive to work fast or under budget. I am not exaggerating this … if anything, it’s worse than what I have described … very frustrating!

Anyway, I appreciate the advice and will never make this mistake again. I’ll wait however long I have to for the right person in the future.

As for this fiasco, I’m forced to make the best of a bad situation because of money constraints … we have a lot left to do on this house (mostly inside), and I still need to get gutters up.

Good advice, if I can find a roofer whose honesty and craftsmenship I can trust. Seriously, though, I am going to have a good roofer take a look at this, but I’m scared to death what else he may tell me.

I would suggest that you use the “find an inspector” feature and find a NACHI inspector in your area. He (or she) usually knows the area, the contractors and can point you towards a good one.

let us know how it goes.

So, I received at least one red square, I assume in regards to my posts on this subject. Anyone have the decency to step forward and actually let me know why?

I couldn’t care less as to what my reputation is on this site, it’s the pincipal of the matter.

The sideing should be 2" off of the roof deck and properly flashed. Caulk does not belong on a roof.

Now that’s one shoddy install at the sidewall transition area.

This illustration will show you the best way to properly flash a sidewall area.

Nice pic. David,

imo the one going up the wall when it comes to a stucco application needs to be a minimum of 4 inche’s to have the proper lapping of materials.

Do you mind if I ask where you got the pic?

I own the Carson Dunlop "Illustrated Home CD".

I have tons of illustrations on file.