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Structural Beams in Atrium

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Anonymous

My wife and I are in escrow on an atrium model in TerraLinda and we are REALLY excited to be part of the Eichler community! We've always dreamed of owning an Eichler and look forward to restoring this house.

It seems that the two structural beams that run through the atrium were cut and capped (the beams are no longer continuous through the atrium). We assume there was dry rot or fungus and the owners at the time decided to cut them instead of treating them.

Does anyone know of a way to restore the continuity of the beams without doing major structural replacement? There was an article in the Eichler newsletter a couple of years ago about someone who restored the ends of beams that were cut off by attaching "fake" beams on the ends.

I did a search in the archives on this topic but didn't find anything.

Any thoughts??

Ben
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Joined: Aug 12 2004

Suggest you have an architect who has structural engineering background review this.

All of the Ecihlers I've seen with an Atrium had those beams as part of their main structure...like a "back bone" that holds the building together.

Maybe just being overly cautious, but best to have someone with structual background take a look.

Yes, it can be made almost like new again. Same person who reviews will have the knowledge to design and draw up plans.

Basicly steel gusseting bolted to the old and new replacement. The gusseting must be long enough onto the old/new to distribute the forces from the new to the old. Bolts/wahsers/nuts through as "wood" threads won't do for this. It should have a "bottom" cup to hold or not, depending on how you want it to "look".

A welded assembly would be best and not that much more.

Painted okay, but I'd suggest hot dip zinc (galvanized), then powder coated to the color of your choice.

Anonymous

Thank you a quick response.

Your points are well taken. I will set up an SE inspection.

You are probably right about the gussetting and method for transferring lateral forces, although it is a bummer that it wouldn't have the look of a continuous beam (if I'm visualizing what you describe).

It's so great to have a support group!!

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Joined: Mar 3 2005

The beams are not one piece from the front of the house to the entry loggia. We live in a Terra Linda Eichler atrium model designed by Claude Oakland. We were thinking of some remodeling and had an architect investigate. The beams in the atrium START in the atrium bedroom wall. So it would be possible to replace the beam. This might be more expensive than the steel approach and would require a skilled contractor. We can refer you to an excellent architect from S.F. and some teriffic Marin contractors that show up, do what they promise and do it well. Enjoy the house, they're great.

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Joined: Jul 7 2004

We bought an atrium model in Terra Linda in July 04. (Anshen and Allen's E-111). There are two beams that run through the atrium. During the inspection, the inspector determined that one of the beams in the atrium had dry rot and needed to be replaced. It was a simple fix that my contractor took care of and it didn't take much time or money. We did not need an architect. The beam in the atrium does not run the length of the house; just the length of the atrium. If you want my contractor's name or the name of my inspector email me at lchapman@nixonpeabody.com. Good luck and congratulations on your purchase! Laura Chapman

Anonymous

Thank you for your input. I will confirm that the beams in our (future) atrium model are not continuous. For some reason, I believe they are continuous.

I would welcome a referral for a reliable contractor in Marin. Here's my email address: akawahara@att.net

We will be moving from SF to Marin and don't have a handle on reliable local trades.

My wife and I are architects (although I left the profession) but thank you for offering the architect referral...

Ben
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Joined: Aug 12 2004

kawabunga wrote:
... although it is a bummer that it wouldn't have the look of a continuous beam (if I'm visualizing what you describe)....

I've noodled that one for possible future work.

I like the "hardware" look, but that's me. Better if it's been painted to match and it's "neat" in design/construction.

If someone didn't want the hardware visiable, I'd have it covered with planks of wood finished to look like a larger cross section beam. A good tradesman can do this easily, plus it's "way up there", so no close inspection by nosey buddies... :)

Many Eichlers have their main beams in several sections and only two "c" or "U" staples is the only way I can describe them. Really about 5/8" or 3/4" dia metal rod (assume steel) bent into a "C" or "U" shape and pounded into corresponding holes in each beam. Both sides, so assume two pwer. Maybe rounded ends so they can be pounded into undersized hole as holding method.

I see that as only longitudinal strength and no/little lateral and the rest of the structure handles that aspect on the ones I've eyeballed to date.

If they aren't structurally required, or their loading not that high, maybe this idea I've also noodled.

Buttress or sister the original beam stubs and fill the top/bottom with matching to simulate a "solid beam". Again a good tradesman can do this and not be noticed from below. Guess cross webbing internally ever so much distance to keep it from bowing.

Since exposed to exterior weathering, care on the seams/joints/etc to keep it from deforming. Mainly the top, which is not visiable, so many choices.

If money no matter, laminated and fastened to the stubs. That might have a kwel look to it if clear coated. Then exposed hardware would look nice/appropriate.....a bit commerical/industrial.

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Joined: Jan 4 2004

Atrium Beam replacement is really not such a big deal to any experienced builder. It is really easy to over think these issues; and it is my experience that people tend to react emotionally when they first realize that a roof beam needs to be replaced.
First of all, most beams that span the atrium split or butt over the posts in the entry area, as weel as the bedrooms or whatever wall supports them on the front side (certain models don't follow this trend).( Also, I have yet to see one doug fir beam over 24 feet in length, which makes it necessary.)
It makes for fairly easy replacement.
Second, having a SE design and draw plans would likely cost more than the replacement of a single or perhaps both beams.
The real problem is that the original construction of many of the structural aspects of Eichler post and beam constraction, would not pass current engineering calcs, and consequently, not ever be permitted if replaced like for like, beacse it is required to have 2" of solid material supporting them, and generally every engineer that I have worked with prefers a full 3-1/2" post on spans exceeding 14 feet.
The good news is that the atruim design has about 1/4 of the roof load as a regular beam, because there is nothing sitting on top of the beams any where near mid-span, where the beam is under the most load.
The atrium beams simply provide continuity from the fromt to the back , as is with most post and beam construction, and that is where the structure (along with the siding)receives a portion of the lateral load support (to prevent it from becoming a parallelagram). By today's standards, there is not a licensed engineer that exists that can make the math work on the original design.
Another important point is to have the carpenter install flashing along the top of the exposed beam to prevent this from happening again. You can avoid this by semi- annually inspecting the paint and re-applying paint as it wears off.
Remember that these houses have been in California along and active tectonic fault system for 50 years, and have done ok so far; in 1989 I had not heard of anyone in the SM highland needing to replace windows, and there is no tempered glass in the huge picture windows.

Unfortunately, I don't have anyone in my company willing to deal with the Marin commute to look at your home, but Robert Hart deals with this stuff all the time (he is on this site as an advertiser). You can always email me for advice, which I am happy to offer as often I need a break from working on estimating.
Good luck.

renman

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Joined: Mar 24 2004

Hi,
Does anyone has a mature tree in the artrium and the truck is against the
beam? I am very concern about the beam. I almost remove the tree but decided to leave it for now. The tree is as old as the house and provide shades but it may damage the structure.
I am considered to have a cable to pull it away from the beam but not sure if that will help.
Does any one that know about it can give me some input?
Thanks
Diana

Joined: Mar 2 2004

Diana,
Mike Burch at Davey Tree 408-453-3389 can help you with your tree.

Big trees are pretty tough. I doubt that you can cable the tree to your house without maybe pullling parts off of your Eichler. At any rate, I didn't see the tree as a potential problem when I inspected the roof last year. I'd still see what Davey has to say about the tree.

Anonymous

Thank you all for your input.

We had our home inspections today (home, roof, pool, fireplace, pest and structural). Regarding the atrium beams, the structural engineer (licensed SE in CA) determined that the cut beams don't impact the structure of the house. He was concerned that the beams were acting as a drag strut and was connected to a bearing wall. Of course, he said while the cut beams did not jeopardize the structure with respect to the original structural design, Eichlers couldn't be built today due to more conservative design standards.

The one thing he said about replacing the beams was that it would be much simpler to do if / when we re-roofed the house, since it would be easier to nail the roof decking to the new beams when the roof was off.

We are still interested in either having the beams replaced OR create a beam extension to make it look like the beams runs through the atrium.

Renman, I'm wondering what you think about what my structural engineer said about the nailing of the roof decking to the new replacement beams. How can you replace the beams AND nail the roof decking to the new beams without taking off the roof?

Ben
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Joined: Aug 12 2004

Shear strength was my thought too, as Eichlers are so top heavy (worse if there's 2-3 layers of roofing) and the shear wall of glass not going to be there after a couple of cycles. I'd guess the 3/8" paneling about the same shear strength as 1/2" sheetrock.

Really depends on the layout of the house and the direction of the ground movement.

If me, I'd have a new extended roof over the atrium. The new extruded polycardonate matrix panels. Clear, smoked, etc. Light, double panel and strong. TAP Plastic in San Mateo carries and has the brochures (where I got the idea a few years ago).

Design it extended above and beyond the existing atrium. The super structure can then tie the old beams together. I'd use steel angle iron or square steel tubing. Galvanized or powder coated. Nuts and bolts with some welded gusseting to the old beams.

No gutter or edging required, as since it extends beyond, drip line over the roof itself and out of sight.

Go nuts and make it motorized to get it completely out of the way when wanted.

Height part of the design metrics. Allows free flowing air, but not stormy weather in.

Joined: Oct 22 2005

Seems like many people have problems with atrium beams and dry rot.

So, can these beams be removed without the house imploding? We've made a cover for the winter that has similar beams to carry out the "look" so having duplicate beams isn't really necessary to carry out the architecture.

Does anyone know if these beams can simply be removed?

Our model has beams that are flat- straight across, in line with the flat roof.

Thanks for any ideas,

Cyndi

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