Hi Everyone,
Just a lowly HO and lurker with a question. I am trying to design an addition, at least in a very general way – size, floorplan and layout. Hope to then have drawings done so I can get bids. The idea is that everyone will be bidding on the same design.
The difficult part is determining the size and shape of the addition because of not knowing what the limits are.
Part of the addition opens a load bearing wall between the kitchen and dining room while at the same time extends both rooms. Obviously, a beam needs to replace the support wall but how big can the opening be. It will be a single story addition. The present wall is 13′ and I would like to enlarge the room by 3′ to 6′ with no wall at all. The opening would start about 2 feet from one end so the span would be 14′ to 17′.
Is this too long? One contractor told me only a 12′ opening max and it had to end where the outside wall is now. Makes sense but I than how are rec halls built that have huge open spaces? I just want to make sure I don’t spin my wheels on something that cannot be done but I also want to know what all the possibilities are.
Thanks in advance for your help.
Replies
So, it's a center bearing wall that you want to replace with a beam and end supports... Is the part of the house where the kitchen and dining room are located one story or are there rooms above? What is below the kitchen/dining room - crawl space? Basement? There might well need to be a pier added down there.
After that, how tall can the new beam be? Or, in other words, is the beam to be a flush beam up in the ceiling that is not seen at all? If so, what is the size of the ceiling joists, which again brings me to wonder what is above the existing rooms you want to open up and extend?
Thanks for your reply. There is a bedroom and bathroom above the dining room and kitchen. There is a full basement below but the addition will have a crawl space.
Preferrably the beam would be flush with the ceiling but if it needs to show, so be it.
The house was built in 1959. It is a cape cod style. I believe a full dormer for the bedroom and bathroom was added in the 70's.
Any size opening/beam is possible. You can always do it with steel if necessary. All you need is a competent person to design the structure. See an architect and/or engineer.
DG/Builder
If you are unable to understand your structure well enough, to tell what kind of load, in pounds per lineal foot, that wall is picking up in load, you will need to hire an engineer.
Your opening can be as large as your imagination, as long as there is enough overhead space to pack in a beam. The beam can be wood, engineered wood, or steel, depending on your situation.
But let's say you have it all resolved yourself, and that your bearing wall is picking up something like 844 plf, part of which is snow load coming from the roof, so you need to design for snow area, 115 percent load duration. The specifiers guides at the TrusJoist MacMillan site will tell you what kind of LVL beam might work for you.
Your bearing wall is now creating a relatively uniform loading upon whatever is beneath it. Cutting in an opening will replace that uniform load with two point loads under the end support members of the new beam. Whatever is below will need to be looked at, structurally.
It sounds to me like you want to develop a fairly complete bid package of drawings and specs, in order to put the job out for competitive bidding. This opening, and how to do it, is an important piece of the puzzle. You're gonna have to resolve all this so it is clear on the plans what the contractor is to do.
You are well advised to hire a professional to analyze things and provide all the structural input, and unless you are good at producing drawings, another professional to produce for you a bid set of plans and specs.
In the post before this one, you see Matt is asking some questions to try to get to a solution for you. But I can tell you, this forum is not the place to get this resolved. It is a totally inefficient way to develop all the data needed to properly size your beam, its end supports, and do whatever necessary structurally below. Furthermore, you have no idea of the qualifications of any of us responders to handle the problem.
Get some local help!
Edited 3/4/2006 11:31 pm ET by Stinger
Stinger - you're killing me with all the technical stuff! Just kidding. I understand most of what you are saying and you have made me aware of something I had not considered and that is the support needed from below. If I have this right, the beam size is determined by the load and with proper support from below, can be whatever size I need?
I really did not expect to get all the engineering and architectural information needed on this board but just enough to keep me going in the right direction. I have lurked a long time just soaking up information so I can make intelligent decisions and be able to select a capable contractor. I know it is impossible to supply solutions without knowing all the facts. Actually, I feel the knowledge I have obtained has made this venture a little less frightening and taught me how much I do not know nor ever will. The respect I have for the pros has been heightened also. Now my only dream is that a crew of the gentlemen on this board will get together and do this project for me so I would'nt have anything to worry about!
So, after all that, do you suggest contacting an engineer first, then an architect? Or does the contractor handle the drawings after the engineering is completed?
ac... ask around.... a lot of what you are concerned about is defined in the code
and any competent designer can conform .. or the beam can get sized and footings spec'd .. it's the rest of the design i'm talking about
IE: you can hire an architect, a designer, or a design / build firm..
if you do some local research you will find someone who can take your ideas and turn them into the addition of your dreams ( well , almost ).. once you have the design you can move on to the executionMike Smith Rhode Island : Design / Build / Repair / Restore
I beg to differ on one small point, Mike. The OP has stated a desire to develop a complete and comprehensive bid package of plans and specs so he can put the job out for bid and get truly apples-to-apples quotes.
He can only accomplish that by getting this design work and spec development done by either himself, or an architect, or good designer. A design/build outfit like yours is probably not the way to get this done.
IMHO, and stop me if I am wrong, design/build firms are not in the biz to do just the design work, then stop, and turn the package over to the client so the client can put the job out for bid.
He can try this alternate, though, but he runs the risks of getting bids on widely differing scopes. He can contact a couple of competing design/build firms like yours, but only after he has resolved in his own mind exactly . . . and I mean exactly . . . what he wants done.
He'll have to sketch it all out, plans, elevations, sections, window sizings, specs for windows, doors, trim, room finish schedule, yadda, yadda, yadda. Only then will he have those two design/build guys bidding on the same thing.
One might end up saying he'll head off that new opening with a two-ply LVL at 11-7/8 depth, the other might say he'll use a W8x12 steel beam, but so what?
well, gene...... imnsho... no matter how detailed his design gets, he will never have two contractors bidding on the same job.... never, ever, ....... never
what he wants is an addition..
what he needs is a team to make his desires reality
he has not been able to get a plumber to respond for two weeks.. this project begs for a design / build firm
or.. let's take it the other way... he "designs"it.. what do you think the odds are of a successful design that allows for good bids ?
or , he finds an architect with vision who gives him a great design,,, NOW he has to find a builder who will execute the design , incorporating all his desires and the architect's vision... good luck
or he does some due diligence and finds a design / build firm who's work he likes, who comes highly recommended... who is compatible
one limiting factor here is the scope..
additions are meat and potatoes to small design / build firms like mine..
which way would you recommend he proceeds ?... hmmmmmm?
Mike Smith Rhode Island : Design / Build / Repair / Restore
Mike, of course you speak from the design/build viewpoint. How can you not? It's your business, right?
But the way I read the OP on this, he wants to end up with a few competitive bids from responsible and well-qualified remodelers, for which each has bid on the same well-defined scope.
In all your years of doing business, you certainly have come across some potential clients like this. Right?
It takes all kinds to make the world go round, and some people are like this. They feel more comfortable going this route than going down the design/build path.
As for architects or designers capable of cooking up a good bid package, they are out there, but maybe few in number in some markets, and hard to find. A friend of mine is an architect out in Lake Forest, IL, and could do this with both hands tied behind his back, but he is probably unique. Built two houses for himself and his family, from concrete work all the way to final finish.
Having spent a long time on the commercial side of this biz, where drawing sets in rolls are as thick as trees, and the specs stack up like the telephone directories for greater NYC, I don't buy your position that a truly well-drawn and well-specified job will come out completely different when done by two different contractors.
That is what a good set of plans and specs are for . . . to see to it that the work, when executed, matches precisely the vision of the owner.
Design/build is a perfect route for a client whose vision is somewhat blurred, and wants to count on the design/build outfit to flesh it out for them. But for someone whose vision is absolutely crystal clear, right down to the colors and model numbers, the cabinet knob types and sources, etc., design/build doesn't do it. A design/build firm can execute the build side of it, but the design side is already done before they get there.
But hey, what do I know? Maybe this guy is right there in your operating territory, and you haven't found each other yet. When and if you do, you might just make a highly successful job of it, together.
Thank you for all the replies and conversation. Yes, I was asking the wrong question. It is the length of the beam, width of the opening that was the concern. If it is 1" in width to 1' in length than it seems the beam would be pretty monstrous.
There too many variables to mention involved with this addition but at least the beam question is clearer. Just needed to know what my limits and options are. Don't want to get too crazy but also do not want to be saying "duh, I should have done this"
No offense, but the design/build thing did not work for me. Spent $2200.00 for the addition and an upstairs bathroom redo and received drawings and designs I could have done just to get a price. The next two places I called wanted a design fee also. If I kept going that route, wouldn't have anything left for the construction.
The probability of having to add support in the basement makes me think that I will have to piece meal this. In other words, my budget now seems inadequate. I'm not sure design/build firms are the way to go for this, but would like one company to do it all. There are two NARI award winning remodelers in the area but are probably way more than I could afford but would probably be worth it. If any of you guys are going through a slow period and need work I can keep you employed for a long time ;)
What I thought was going to be a fun and exciting project is now giving me ulcers and sleepless nights. I am a single woman and often read about shoddy work and people losing their money so I am trying to educate myself about the process. Thank you all for taking the time to reply.
I cannot quite tell what you mean when you talk about size. It's unclear to me whether you mean the size of the addition, the size of the wall opening going into the addition, or the size of the beam.
All this can be resolved by hiring a competent architect or residential designer.
As I tried to say in my earlier post, until you boil this down to a documented scope of work, you cannot be talking to contractors, whether they are remodelers only, or design/build remodelers.
And forget that the plumber won't call you back. When you have turned the job over to a contractor, he'll get the plumber there when needed.
One more force to consider -- shear. Whoever told the OP that the opening would be limited to some certain width may have had shear wall constraints. Steel beam with engineered connections to steel posts can fix that, but it can also cost . . . .
Seeking perfection in an imperfect world is a fool's errand. Making something look perfect is a whole 'nother story . . . .
>> So, after all that, do you suggest contacting an engineer first, then an architect? <<
Generally, there are 2 ways to go:
1) You hire an architect who would also be qualified to do the engineering work. The advantage to this option is that an architect is possibly more artistically inclined and might be more likely to come up with an innovative design.
2) You hire a house plan designer (plans drawer) to put your ideas down on paper (or convert your sketches to working drawings) and then hire a professional engineer (PE) to set/verify the beam sizes, etc. A plans designer will likely have a connection for a PE. This option #2 is the way my company builds houses and is likely the most economical. A designer will likely be able to answer your "what is feasible question" and be able to tell you that no, you can't hang a 17' long beam from the clouds :-). Then the Engineers "cements" the design by specifying the particulars and stamps it.
Re the above discussion of the design/build firms, this would take the place of the designer and you might well even get a more "grounded" design. Also, the design/build will undoubtedly have a business relationship with a PE to get that part of the deal out of the way. Some of these design/build firms will draw up a set of plans for a price, which would then be "refunded" when/if you award them the job. To make your apples to apples comparison, you would have to add this design price to other bidders figures.
In the above paragraph, when I said "grounded design" what I meant is that it is not at all unheard of for a archi/designer to draw-up some detail that can't be built - and a PE can even stamp it because he doesn't entirely think it through. This is not likely to happen with a design/build since a company like this actually has to deliver the finished product.
ac... before you start looking for a contractor.. i'd look for a designer
here's my philosophy:
bad contractors are everywhere
good contractors are plentiful
good design is where it all starts.
a good contractor can never deliver a great addition based on a bad plan
from your description and questions, i'd say you would benfit most from design help
Thank you for your reply. I have worked with a designer who gave me the basics I am working with now. Of course, the size of the addition is the deciding factor and that is why I needed to know how large it could be.
I have met a large number of questionable contractors and lost money to one already which prompted me to do my own design and drawings before I move ahead. The whole idea of dealing with this is sometimes overwhelming. When I think of what can go wrong, the panic attacks come. For gosh sakes, I have been trying for six weeks to get a plumber to come to my house and have failed and I think I can get an addition built? :)
AcCable,
You're asking the wrong question.
Ya' see around us contractor brutes, asking how large a beam should be, means "How deep and thick should it be."
You need to ask "How long can it be?"
Then we know to tell you "Oh, a beam can be couple hundred feet, or so, long."
That's interior design stuff. An engineer can't help you with that. It's not his field.
After you decide how long you want it, an engineer can tell you how large it must be to be that long. He can also tell you what support you will need from earth to beam and whether or not you would need mid span support columns, (for a small beam.)
If you also give the engineer any constraints, like, it must fit in the existing ceiling space, he can tell you if you mu$t u$e a $pecial beam.
What you must tell the engineer:
All dimensions and materials of everything above and below the beam
All constraints of any column placements under the beam to earth
Any e$thetic de$ign con$traint$
How long the beam is
The cheapest esthetics will be to allow both end columns to extend 6" into the floor space and to allow the beam to extend below the ceiling. The support to earth for the exterior end is easy, since you can build that into your new foundation. You may have to build a new column, with footing, in the basement under the interior end.
SamT
Just to give you a rough idea of what you're looking at - The general rule of thumb for beams is one foot of span for each inch of depth. In other words, a 12" beam for a 12' opening. That's a good starting point. But the exact size of the eabm and what it carries still has to be figured based on the actual load on the beam.
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