General construction question

[jaspermac]

I am adding on to a building that has Hardie board ship lap. I’m adding on by using gable trusses that fit under the existing eaves and will keep the same pitch, just a bit shorter therefore tighter span.

the question…I want the new trusses to go directly onto the existing exterior wall but how to I deal with the gaps in the hardie board? I thought about nothing the wall but I don’t want to risk water coming in and have to renail each board. I’ll have plywood decking that will have to go on the truss as well. I was hoping to flash it and may just have to cut individual flash pieces to fit each board.

ill post a pic to help show the gap.

whats the correct way?

[aggie2000tx]

I can’t picture in my head what you are dealing with concerning the hardie board.

you said you were using trusses to go under the eaves. Why are you running a flat board on the hardie?

[PYBUCK]

I can't picture what you are doing either. You mentioned a tight fit under the eaves, but it looks like there are 6 -6" ship lap hardy boards in your picture. Is the eave 36"? If so, that isn't a tight fit and should be an easy addition.

[Txhunter3000]

To do it correctly you'll need to take the siding off, put your truss against the plywood or studs. You need to install the correct flashing for the roofing type and then put the siding back up.

[jaspermac]

This may show it better. I’m screwing the new truss into existing wall with Hardie trim

[mikemorvan]

To do it correctly you'll need to take the siding off, put your truss against the plywood or studs. You need to install the correct flashing for the roofing type and then put the siding back up.

agree. I’m the grand scheme of things the siding cost shouldn’t be that big a deal. This will make the total addition easier, as well as being right.

[Southbound 85]

I’d cut the hardie on the eave the shape of the new truss and go wood on wood and flash under the old hardie and under your new shingles.

when doing this you might run into nails trying to slide flashing under existing hardie. As said above, the correct/best way is to remove the hardie & go back trimmed out pretty.

[E.TX.BOWHUNTER]

You could cut the Hardie as mentioned but I would remove it all. It is not that expensive or difficult to install. It will be a much cleaner and better looking job too. Paint it before you install it. Good luck

[aggie2000tx]

You will need to take the hardie off to do this correctly. You will never be able to get it sealed off to prevent leaks putting it on top like that.

[Pineywoods]

This may show it better. I’m screwing the new truss into existing wall with Hardie trim

There are different ways to do this and some have been mentioned. If it were mine, I would just remove the hardi on that gable since it's a small area, and place your connecting truss directly against the framing on the gable end. You'll need flashing behind the new siding where it meets the new roofline. Leaving the existing hardi and cutting it back might save a few bucks but wouldn't make it easier in my opinion.

[Dale Moser]

Yeah, take the siding off. You'll spend more time trying to half *** it, it won't look as good, and it will cost more down the road.

[jaspermac]

Thanks for the advice. After looking at it again today, it won’t be that bad taking all the siding off. I should be able to reuse some of it.