Still the Aristocrat of Bungalows
The Sears "Ashmore" House
424 Oliver Ave. S.
Minneapolis, Minnesota
Adjustments
After the decision was made to remove the wall between the two bedrooms in the early planning stages, both general contractor and architect returned to the house to determine if the wall being removed was supporting structural loads from the roof, or ceiling. This task is often fairly easy when the basement walls and ceiling haven't been finished since any load-bearing walls on the first floor need to be supported in the basement and the required structural members are usually obvious. In those instances when structural members are covered, it is sometimes possible to determine the location of bearing walls by identifying the alignment of walls on multiple levels or from room proportions since structural members usually span the shortest possible distance.
"The Ashmore" structural system seemed obvious. The wall being removed had no direct support in the basement. The closest basement wall ran parallel to, and about 18" away, from the bedroom wall above. Since the span of the first floor joists was also parallel to this basement wall, loads couldn't be transferred down to the basement wall. All the visible evidence indicated that the bedroom wall wasn't load bearing and could be removed without structural implications.
All the evidence that is, until the lath and plaster was removed from the wall and adjacent ceiling. The attic floor joists, which in turn also supported the ceiling, were inexplicably spanning perpendicular to the first floor joists so that they were supported on the wall to be removed. While its unusual but not unheard of for the direction of joists to change from floor to floor, it certainly didn't come close to meeting contemporary building codes since the wall supporting the joists was not itself properly supported in the basement. The only token of support were doubled 2 x 8 joists under the wall. The original designers probably got away with this questionable practice because the loads on the attic floor were so minimal.
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| Posts were inserted in the walls to support each end of the new beam. Large Image | | |
A new beam would be needed to replace the wall between bedrooms so that the attic floor, and bedroom ceiling, were properly supported. The easiest way to add a beam in this situation is to install it under the floor joists so they are physically resting on the beam. The downside of this approach is a beam that is apparent in the finished space. Unless this beam defines two separate functional areas or is worked into an overall ceiling design, it screams that a wall has been removed. This however, rarely results in an ideal appearence.
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| The new beam projectd above the attic floor. Large Image | | |
While there was an overall coffered ceiling treatment designed for the joined rooms, the expressed beams in the design didn't align with the location of the actual beam. Even if it did, the actual beam would drop well down below what would be appropriate for the design. In any event, Paul planned to eliminate the coffered ceiling to save costs.
In order to hide the beam a more complicated approach was necessary. While temporarily supporting the attic floor joists on each side of the new beam, the existing joists wold be cut off to create a slot for the new beam. After the new beam was reaised into place and properly supported on each end, joist hangers would be attached to the beam to support the original joists. Using this method, when a new beam is the same height as the original joists, it can completely disappear into the existing framing depth between floor and ceiling. However, when a beam is deeper, it usually projects below whatever distance is necessary and is expressed as part of a ceiling treatment.
By the engineer's calculations, the beam required here would need to be 14" deep, almost twice the height of the existing joists. Since it wasn't possible to use a ceiling treatment to disguise the bottom of a dropped beam, the new beam would need to project above the attic floor. Since this area would be used for storage and new air conditioning equipment, the interruption in the attic floor was something that seemed to be workable and the best alternative.
With this problem solved, another appeared. As the plumber began to rough-in his plumbing, he discovered that getting the toilet in the required location would center the drain in a beam previously hidden in the floor. The location of this beam was another surprise.
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| Reinforcing the existing beam along with other new framing (light colored) allowed the existing beam to be cut out for the toilet rough-in. Large Image | | |
The area of the bath, as well as the two original closets that were being incorporated into the bath, project out a couple feet beyond the rest of the house. This projection isn't supported by a foundation however. Instead, the floor joists canteliver out beyond the foundation with the rest of the room supported on these floor joists. The conflicting beam was used to anchor the end of the joists that cantilever. The surprise was that the location of this beam was so close to the exterior wall meant that the cantilevered lenght was about equal to the supported lenght. The usual rule-of-thumb is 1:2. Rule-of-thumb aside, usually for a cantilever of a couple of feet, the joists might extend in another 10 or 12' before being anchored to a beam or other joists. This again ammounted to an unexpeced problem that was the result of what today would be considered inadequate framing.
Working again with the structural engineer, a fix was devised that added two additional 2 x 8 joists to the side of the existing beam so that a section of the original beam could be cut-out for the plumbing. Since one of the cantilevered joists was supported at the point where the beam was being cut out, a header was installed between the two adjacent joists. The center joist was then cut back to the header and supported. And with that change the structural issues were resolved.
Read more about "The Ashmore" House:
Please come back to follow the work in detail as it progresses.
Architect:
Joseph G. Metzler
SALA Architects, Inc.
326 East Hennepin Ave., Suite 200
Minneapolis, MN 55414
612 379-3037
General Contractor:
Mike Otto Construction, Inc.
210 Dean Avenue E.
Champlin, MN 55316
612 245-5826
Structural Engineer:
McConkey Johnson Soltermann, Inc.
241 Cleveland Avenue S.
Suite B2
St. Paul, MN 55105
651 698-5626
