planning an addition to exisiting log home

[boneheads cabin]

First post! Thanks for having me :)
I own a (kit) cabin in the center of Connecticut. It was built in 1980. the kit company was New England Log Homes and are no longer in business.
I want to add on a (approx) 16'x16' addition to the GROUND LEVEL only. Which means i will have a full foundation poured to match the height of the existing foundation (8ft). The addition will join the exisiting house at the exisiting 'walk-out' door that is already in the house. The addition will sit where a patio is now - flat, bricked...easy right?
What is the proper method of tying the new roof into the exterior of the existing logs? Do i need to establish a flat, true surface to flash to, cut into the face of the logs? If so, is that done with a hand planer?
Or can i simply lag bolt my roof rafter to the high-point of the log and fill the gaps with some sealant? Epoxy? Silicone? roof cement?
<if i learn how to post more pics i will>
thank you to anyone reading / replying

tb

[rreidnauer]

First off using sealant/caulk/whatever should always be reserved as a last resort, because it will almost assuredly give you grief later down the road. Funny you bring this up, as it was a discussion me and a few other LHBA members were hashing out this past weekend. Here's what I think is the best way to tie the roof into log walls.
The plan would be to cut a slot into the wall logs about 3 inches above where the new roof will come into the wall. Preferably, have the slot pitch upwards into the log some. (15 ~ 20 degrees is plenty) To make it a straight cut, nail a 2x4 on so the circular saw has a straight edge to follow) The groove depth is determined by the irregularity of the wall, (like when sawing a diagonal cut) but you want to assure you are as deep as the most recessed section of the wall. Then you need to bend the log flashing on a brake to look like the sketch below. (indicated in red) With the new roof meeting the wall, do the standard step flashing (indicated in blue) when roofing, and insert the log flashing afterwards. I don't recommend caulking the groove to hold it in. Rather, just leave the "J" bend open a little, and drive it into the slot with a flat bar or something. The pressure will keep it in and the edge of the flashing will probably "tooth into" the wood making it pretty difficult to be pulled out. Not only does the "J" bend secure the flashing, it also acts as a last defense to any windblown rain that might go into the groove, so make sure you bend it in the orientation shown.
http://img.photobucket.com/albums/v328/titantornado/flashing.jpg
In a case where the roof pitches away from the log wall, you can omit the step flashing, and simply add an extra bend to the log flashing to extend onto the roof surface.

[boneheads cabin]

wow - that is a pheniominal, simple, effective plan. Thank you very much. My bro in law is a copper flashman (?) and i will pass this by him to see how tight he can make that loop. Very smart, thank you

[StressMan79]

Keep in mind that your home has settled all it is going to, if you add a kit style addition to the back, you will get additional settling. If I were you, I'd put a stick framed addition with cedar shakes for siding.
-Peter

[hemlock77]

First post! Thanks for having me :)
I own a (kit) cabin in the center of Connecticut. It was built in 1980. the kit company was New England Log Homes and are no longer in business.
I want to add on a (approx) 16'x16' addition to the GROUND LEVEL only. Which means i will have a full foundation poured to match the height of the existing foundation (8ft). The addition will join the exisiting house at the exisiting 'walk-out' door that is already in the house. The addition will sit where a patio is now - flat, bricked...easy right?
What is the proper method of tying the new roof into the exterior of the existing logs? Do i need to establish a flat, true surface to flash to, cut into the face of the logs? If so, is that done with a hand planer?
Or can i simply lag bolt my roof rafter to the high-point of the log and fill the gaps with some sealant? Epoxy? Silicone? roof cement?
<if i learn how to post more pics i will>
thank you to anyone reading / replying

tb
Hey we are practicaly neighbors, We are building a but n pass cabin in Ashford Connecticut. Are you familiar with the history of New England log homes? My understanding is that they used some fairly toxic chemicals to treat the logs as a protective measure against fungus and insects. I came across this a few years back when doing research on log homes. Here link on the redevelopment of their site. <a href="http://cdcsb.org/?page_id=20">http://cdcsb.org/?page_id=20</a>
I am not trying to rain on your parade, I just figure it might be need to know information.
Stu
<a href="http://s165.photobucket.com/albums/u64/hemlock77/">http://s165.photobucket.com/albums/u64/hemlock77/</a>

[boneheads cabin]

Thanks, yes i understand settling and log shrinking etc. this is a concrete addition to the foundation with a wood roof on top. The foundation is designed such that i could up to expand the log / living space above. If that ever happens, i will decide on materials then. thanks

[boneheads cabin]

Howdy Neighbor...yes, i've read what little is out there on NELH. although we were concerned at first we realize there are alot of building materials and practice with a somewhat sketchy past :( We love the place, bought in 07. the logs are in great shape. i spent last summer Weather Sealing the exterior. We plan on doing a fresh clear coat on the inside soon.
Thanks for the welcoming.
HEY - QUESTION ABOUT THE NEW ROOF- how 'slight' of a pitch can i go on a rafter-type roof system. i got that rear window to contend with. CAN I GO AS FLAT AS A 3/12 PITCH?
thank you all again

[rreidnauer]

The standard for asphalt shingles is 4/12 minimum. You can go down to 2/12, but make darn certain you use ice and water shield all the way up.

[hemlock77]

Just curious. What will be the use of your addition? A quick glance of your rendering suggests it is utilizing passive solar design.
Stu
<a href="http://s165.photobucket.com/albums/u64/hemlock77/">http://s165.photobucket.com/albums/u64/hemlock77/</a>

[boneheads cabin]

thank you...any comments on a possible metal roof with that flat of a pitch?

[boneheads cabin]

The purpose of the addition is to expand the basement 'living space' which is currently a recording studio - low key, private. The addition will attached to the walk-out of the existing basement and will reside on what is now an unused, ugly brick patio that traps leaves and snow. The addition will be (2.5 walls) exposed 'above ground' and the majority of the wall area will be glass. both sliding and fixed. the idea is 'open-air' in the summer, sealed in the winter.
The new concrete walls will be formed with insulated panels that remain once cured. The insulated panels have fur strips every 16" OC (outside and in) for paneling/sheetrock / stoneface / siding/ . the roof will also be SIP's with T&amp;G pine on the inside and OSB on the outside for asphalt or steel roof
Eventually the brick floor comes out and a slab is poured on an insulated base. Possibly with radiant tubing? solar panels on main roof?
The 10+yr plan is to expand upward on this new foundation that is being built now, adding on to the cabin living space, adding large windows etc...
see quick link where i can post pics, ideas...etc
All pics on left are the project at hand. The pics on the right is the 10+yr plan after i win the lottery :)
<a href="http://www.boneheadstudio.com/cabin.html">http://www.boneheadstudio.com/cabin.html</a>
thanks for playing along
tb

[rreidnauer]

thank you...any comments on a possible metal roof with that flat of a pitch?

I don't think metal roofing is used on pitches below 2/12. Just due to the nature of the product, it would be difficult to properly flash corregated or standing seam metal at the wall to where it will repel windblown rain up such a shallow slope. (the wall flashing relys a lot on gravity to keep the water from getting behind it) That flashing would probably need to be caulked, and I hate that because the caulk will eventually fail, so it's another maintenance issue that's in an "out of sight - out of mind" area.

[StressMan79]

I believe for the warranty to be good they specify 4/12, min...on all products I have seen anyway.

[clairenj]

HEY - QUESTION ABOUT THE NEW ROOF- how 'slight' of a pitch can i go on a rafter-type roof system. i got that rear window to contend with. CAN I GO AS FLAT AS A 3/12 PITCH?

we had a roof pitched at 2.5/12 however, our shingles were overlapped more than standard and we used ice and water shield underneath. We only had one incident in 13 years and that was ice-damming which happened to everyone in our area one particular storm. We had just put gutters on and that was a big mistake with that pitch. our overhangs were sufficient and so we had no gutters for years, but then we added a deck along one side and across the back gable side and we were trying to redirect the water from falling (and freezing) on the deck. the ice storm was severe, followed by tons of rain and sleet. With the proper overhangs and pitch, you don't need the gutters. but then you get water dumping onto your walkways and decks. so, a porch is the next answer ( $$$$$) choose your battle, in the end it's always about water.