[msh1285]

Currently purchasing an 1880s Cape Cod style house and figure I will be spending quite a bit of time on these forums going forward. Prior to moving in we'd like to do some work on the attic where our bedroom will be.

I've attached a picture from the listing of the current space and one from the inspection behind one of the knee walls.

Before moving in, we would prefer to remove this interior wall that is splitting up the attic area, and also remove the knee walls and probably asbestos insulation behind the knee walls. Essentially strip the attic down completely and add further windows/skylight.

The question is, are the interior wall and the knee walls load bearing? Is it possible to tell from the photos if they just be taken down without issue?

May be difficult to discern here but thought I would pose the question.

Thanks!

 

[Bondo]

Ayuh,... From what can be seen, Ya, those walls are holdin' up the roof, 'n there's no asbestos,....

 

[Mingledtrash]

Ayuh,... From what can be seen, Ya, those walls are holdin' up the roof, 'n there's no asbestos,....

I agree with you that the knee walls are likely bearing but, I do not see how you could possibly tell from a crappy picture that there is no asbestos present.(I am not trying to say someone needs to be scared sh!tless of asbestos but if there is a possibility of having asbestos they should be aware of the risks so they can make an informed decision.)

 

[Bondo]

I agree with you that the knee walls are likely bearing but, I do not see how you could possibly tell from a crappy picture that there is no asbestos present.(I am not trying to say someone needs to be scared sh!tless of asbestos but if there is a possibility of having asbestos they should be aware of the risks so they can make an informed decision.)

Ayuh,.... As I said, I see nothin' to indicate asbestos is present,.....

 

[Daniel Holzman]

Knee walls were commonly used in houses to partially support the rafters. This was sometimes done in cases where the rafter was undersized to span the entire distance without intermediate support. In some cases, the knee wall was used as a support during construction, and was removed after installation, but in your case the knee wall was left in place.

The only way to determine if the knee wall you have is structurally necessary is to accurately measure the span and pitch of your rafters, determine the exact dimensions of the rafters, and perform a strength and deflection calculation on the rafters to see if they would be strong enough and stiff enough without the knee walls in place. This sort of calculation might be done by an engineer, an architect, or a contractor with structural knowledge, but would require a site visit to measure dimensions.

 

[joecaption]

What did they use for roofing on this home?
I've worked on and built many of those attic rooms in the past in both new constrution, modulers and 100 plus year old homes, all had there issues trying to get it to work.
Biggest one by far was trying to get enough insulation in the rafter bays, the knee walls and still allow for ventlation if it was a shingled roof.
Heat rises, all the heat from the lower floor tends to rise to the second floor, you have the sun beating down on the roof, add a sky light and you may as well add a solar panel making it even hotter.
If you do get one I'd strongly suggest you spend the extra money and get an opening one and or one with a built in cover. They even make them with a rain detector so they close if it's raining.
I made all my knee walls with 2 X 6's, if there was already 2 X 4's I'd build them out with 2 X 2's so I could use R19 in the stud bays.
Then I'd add Tyvek on the back side of the knee walls to reduce wind wash.
It's a good idea to also add blocking at the bottom of the knee walls in the joist bays to stop air from getting in under the floor.
Depending on your location that flat part of the ceiling may have needed up to R50.
If forced air HVAC was used for heat and or cooling it was rare to see a return air vent installed with DIY attic conversions compounding the heating and cooling issues.
For lighting I always went with Air tight, I/C cans.

 

[msh1285]

Knee walls were commonly used in houses to partially support the rafters. This was sometimes done in cases where the rafter was undersized to span the entire distance without intermediate support. In some cases, the knee wall was used as a support during construction, and was removed after installation, but in your case the knee wall was left in place.

The only way to determine if the knee wall you have is structurally necessary is to accurately measure the span and pitch of your rafters, determine the exact dimensions of the rafters, and perform a strength and deflection calculation on the rafters to see if they would be strong enough and stiff enough without the knee walls in place. This sort of calculation might be done by an engineer, an architect, or a contractor with structural knowledge, but would require a site visit to measure dimensions.

Thanks! I admit these are some crappy pictures but we are not yet in the house and it's really all I have. I'll try to schedule an architect to come out and look at it the day after we close.

Is there a way to tell anything about the partition wall from the picture?

 

[gregzoll]

You do not need an architect to do anything. What I would do is leave 2 2x4's with top and bottom plates left attached for each group, then go about every six feet and do the same.

Most unfinished attics like this are just supporting the rafters with 1x6's every six feet.

You may want to think about Spray foam for the roof, and same for any walls that will be in the attic space.

Your first item to address after ripping all of that drywall off, would be inspecting for any leaks.

The only bad thing that I can think of for you wanting to do this. Is making sure that you do not hit your head if you plan on placing something along the walls and have a wider walking space.

Since you plan on gutting and remodeling. You are talking permits. If you touch the wiring. You can be asked by the local AHJ to replace any existing regular breakers with ACFI's.

 

[Canarywood1]

If those knee walls were put in during construction, i don't think they would have dry wall on them.

 

[gregzoll]

If those knee walls were put in during construction, i don't think they would have dry wall on them.

Go back and re-read. It is a two part question. His main concern are the walls that have the drywall in them. The other shorter wall towards the outer edge of the roof, is most likely there because this is probably Balloon type framing from looking at the age of those 2x4's.

Either way, he cannot remove those finished walls, without leaving some 2x4's to brace the roof, to help keep it from moving, until he gets the new wall in where they want it.

 

[ktkelly]

I think some of y'all are missing the point, and others are right on.



If you wish to remove both the knee walls, and the wall separating the two rooms you should start by removing all the drywall and insulation, then you can actually see how the framing was done, and have a qualified person determine what you can, and cannot remove before putting it all back together.


When I say have a qualified person do the determination, I mean you absolutely should have an architech, engineer, or possibly a contractor, do the determination. Posting otherwise it irresponsible..

 

[Gary in WA]

I agree with Kelly, get someone on site. You don't need to leave braces or walls before removing existing if rafters are rated for the span (they may sag but not move with sheathing above) -"Either way, he cannot remove those finished walls, without leaving some 2x4's to brace the roof, to help keep it from moving, until he gets the new wall in where they want it."; scroll down to rafter spans- http://publicecodes.cyberregs.com/icod/irc/2009/icod_irc_2009_8_sec002.htm

The worry part for me is the balloon framing of walls extending up some distance above the ceiling joists (2nd pic) without any connection to prevent spreading, removing the knee walls may put added force on the outward pressure of walls from the rafters at the top because of lack of bracing there. A contractor would require diagonal bracing to the attic floor/rafter to prevent spreading. Similar to "B" on pp 8/9 but you are way higher than a floor joist thickness for the required ceiling/floor joist to rafter connections; http://nhboa.net/wp-content/uploads/2015/08/framing-guidelines.pdf


If you remove the knee walls, you are left with the collar ties (ceiling joists) holding the raters together which are too high up and the floor joists are too low; http://publicecodes.cyberregs.com/icod/irc/2009/icod_irc_2009_8_par022.htm You could move them back some, after anchoring the wall/rafter as said first. You may need to sister the existing rafters when moving the knee walls outward to carry the added loads at the new span; http://myconco.com/ComEngProb.html

Gary

 

[mikegp]

Was there a fire in that house? Looks like soot on the right. Might just be my phone.