Hi <!—-><!—-><!—->
I plan to remodel the upstairs of my house that was built in 1910. The plan is to have space for two bedrooms and a new bathroom, or one big bedroom with a bath. The upstairs currently has knee walls and a low ceiling with no insulation or ventilation. Our house is a rectangle, approximately 24×45 with a bearing wall running down the middle. I would like to extend the knee walls from three feet to six feet, giving the upstairs more head room and bigger rafters for insulation and venting. The new walls would then stand proud of the existing roof plane by approximately three feet with the new roof on top. However, that means the new walls supporting the majority of the roof load would be between three to four feet off the exterior walls. The floor joists are 2×6. My plan to support the new walls and roof is to run beams (4×6 or possibly 6×6) along the floor joists every six feet or so. Then, I would built the new wall on a beam that runs perpendicular to the beams in the floor. Our plan also calls for a couple of dormers on each side of the reconfigured roof. We are trying to keep the construction as light as possible because we have an old foundation six inches wide x28 inches high. There is no footing. My questions are; does this sound like a reasonable plan, is it overkill, do I need an engineer, are we going to have foundation issues? Any help, thoughts or ideas would be appreciated. Thank you<!—-><!—->
Replies
sheesh...
did your return key break ?
I don't really know what I'm doing so ... Typing is enough of a challenge.
yeah... well , there are a lot of olde eyes around here that need white space surrounding the little black print
your post was one black blurMike Smith Rhode Island : Design / Build / Repair / Restore
Oops, I guess I need to learn to write in paragraphs. By the way, any thoughts on my project/problem?
break it down and i'll be glad to take a crack at itMike Smith Rhode Island : Design / Build / Repair / Restore
Well, I did not exactly get it into paragraph form, but I sure have a lot of wite space now!
Hi<!----><!----><!---->
I plan to remodel the upstairs of my house that was built in 1910. The plan is to
have space for two bedrooms and a new bathroom, or one big bedroom with a
bath. The upstairs currently has knee walls and a low ceiling with no insulation or
ventilation. Our house is a rectangle, approximately 24x45 with a bearing wall
running down the middle. I would like to extend the knee walls from three feet to six
feet, giving the upstairs more head room and bigger rafters for insulation and
venting. The new walls would then stand proud of the existing roof plane by
approximately three feet with the new roof on top. However, that means the new
walls supporting the majority of the roof load would be between three to four feet off
the exterior walls. The floor joists are 2x6. My plan to support the new walls and
roof is to run beams (4x6 or possibly 6x6) along the floor joists every six feet or so.
Then, I would built the new wall on a beam that runs perpendicular to the beams in
the floor. Our plan also calls for a couple of dormers on each side of the reconfigured
roof. We are trying to keep the construction as light as possible because we have an
old foundation six inches wide x28 inches high. There is no footing. My
questions are; does this sound like a reasonable plan, is it overkill, do I need an
engineer, are we going to have foundation issues? Any help, thoughts or ideas
would be appreciated. Thank you<!----><!---->
it shouldn't be a big deal..... and it does sound feasible
but you really do need an engineer to run the numbers
also where are you located ?
makes a difference as far as wind uplift & snow loads
it's a 1 3/4 storey, and MOST foundations can carry the load
the engineer can save you from overbuilding tooMike Smith Rhode Island : Design / Build / Repair / Restore
Thanks for the feedback. I live in a in western Washington, about 30 min. east of Seattle. We don't have much snow, but we do have some wind. Also, any idea what the cost would be for an engineer?
You are trying to perch an entire roof assembly load ou t in themiddle of 2x6 rafters.Won't work - no way no how.
You need some seerious onsite eengineering/design help on site. No way to get this right online
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
paul... it should be some fairly easy calcs
it's a simple roof with a kneewall, and the span is only 12'
and there are some point loads for the dormers
so... i'd think the engineering fee would be not too bad....Mike Smith Rhode Island : Design / Build / Repair / Restore
not bad, no. $200-500, but it does need to be somebody in the area who knows their things like seismic loads and codes, and who can see the current conditions. His idea as explained might even work but getting it engineered here at BT is dangerous.
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
Good morning,
I just checked in to see if anyone had any more input on my problem and am thankful
for the time all of you have taken to give me some feedback. It sounds like getting
an engineer involved is the way to go. Again, thank you for helping out and using
your experience to point me in the right direction.
best of luck with it. Probably will look pretty from exterior too once you work out the proportions.Now that I think of it, this may look better if you do it a bit wider, which would not really cost more and that would seat the loads nearer to the exterior walls
Give it some thought.
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
Now that I think of it, this may look better if you do it a bit wider, which would not really cost more and that would seat the loads nearer to the exterior walls Give it some thought.
Maybe I completely misinterpreted what the OP was saying. Rather than building a second knee wall further inboard, I thought he was asking about raising the roofline by increasing the actual height of the existing knee walls.
That is the way I read it, IIRC, but what I was suggesting is that he move the second floor walls ( the knee walls that would grow taller to support the new roof) out so they are nearly over the exterior walls now.I forget all the dimensions so I would have to go back and re-read to be more specific.
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
she had the right advise. GET AN ENGENEER.
Are you argueing with me?I think I was one of several who already said that
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no
ok... neutral corners , you twoMike Smith Rhode Island : Design / Build / Repair / Restore
However, that means the new walls supporting the majority of the roof load would be between three to four feet off the exterior walls.
While it sometimes seems like a good idea, rarely does this type of set-back situation end up being worth the huge amount of effort. On a new house it's a building challenge, on a 100 year remodel with undersized floor joists it's not feasible. Now if you said you had an unlimited budget and building it right wasn't a problem I'd be more optimistic, but you are taking this course of action as a low cost way to add space, which it won't be.
2x6 floors barely hold themselves and you would need to add more wood to the floor than it's worth. The fix to hold a roof load would probably be speced as a huge number of LVL's ripped (although one outfit does make 5-1/2" LVL's) or steel, both of which are spendy.
Depending on your soil types, your foundation will almost guarantee all sorts of problems from a structural viewpoint. No engineer or building department plan reviewer I've ever come across will allow a second story addition to rest on a foundation as you've described it. There are a number of fixes, but they aren't cheap.
You definitely need someone familiar with your local building requirements to look at your project and give rough estimates of the various options.
Cost wise, you are probably better off with an addition of some sort, even if it's a two story addition, taking in the area upstairs you have to remodel. This takes care of the foundation problem for at least part of the structure.
The cost of a decent second story addition is more than the cost of an equal amount of new construction. It's simply human nature to imagine that unfinished attic space is better than it really is. We look at a few projects just like yours each year and the costs just don't pencil out to be worth while.
Having said that, if you have the budget for it, these can be fun projects to build since they require a fair amount of serious thought. We normally strip the entire top off a house as you've described and build it new instead of keeping any of the old.
The option we normally suggest is to use spray foam on the existing rafters to bring the attic space into the building envelope and eliminate the need for venting. Then the ceiling joists are beefed up and decked over providing great storage space. An addition takes care of the habitable space requirements.
Best of luck
Beer was created so carpenters wouldn't rule the world.
I would like to extend the knee walls from three feet to six feet, giving the upstairs more head room and bigger rafters for insulation and venting.
I live in the Seattle area and I'm familiar with that type house from the 1910s -- lots of them around here, as you know.
The biggest potential problem I see is that you're working with balloon framing. If you simply extend the "knee wall" (which is really just the top several feet of the balloon stud) upward, you're going to increase the torque applied to that stud where it is tied into the floor joists. That is, right now you have a three-foot-long lever; you are proposing to double that length, and therefore double the applied torque (assuming that the load pattern from above remains unaltered).
I'm not sure this WILL be a problem, but it raises a potential problem in my mind.
It seems to me that you'd be better off to just raze the second floor entirely and platform frame the addition with a standard 8-foot ceiling. Have you considered that possibility? Sometimes, the second floor framing system is floated above the existing attic/ceiling joists. This adds an extra step to your run of stairs, but results in a very sound floor.
Hope that helps.
I just met with a designer down in Issaquah last week regarding an addition to my own house (just outside of Redmond). If you're in King County, you're going to have a tough time getting permitting for a second floor on a 6" foundation. You have seismic requirements to meet as well.
Shoot me a PM if you want a reference to the designer - but these guys are right, you're not only required to have an engineer look this over, you actually need one. You're talking about a cantilevered second floor on a substandard foundation! Who knows when the next Nisqually quake is going to hit...
Good luck,
-t
Hi
My internet has been out for a couple of days so I just checked back in. Wow! It is
cool to see my problem kicked around and I have paid attention to all the advice and
thoughts. Just a couple points of clarification. Our house is not balooned framed.
We would like to move the new upstair wall in from the exterior wall a couple of feet
to a point approximately where our current knee wall is currently. Our foundation is
not up to snuff for new construction and it was our hope that since we already have
a room
upstairs, we could use is as is or with footings for point loads by only adding a
modest amount of weight. We will need a engineer(you all made me see the light)to
make it all work out, but if we use some beams that span 12 feet and support the
wall a couple of feet from the exterior wall on a beam perpendicular to the beams in
the floor, that should give the new walls and the roof they support something to
bear on. I also agree that the most economical way to add square footage would be
to build new and tie the two structues together, but reconfiguring the upstairs
would make the old place look good without changing the character too much.
Anyway, thank you again for all your help.