Replies

1. 
   Guest_ | Nov 09, 1999 02:24am | #1

   *
   Dear KWJ, I've tried to visualize your proposed garage roof and I've been unable to so far. Do you think your engineer is not coming up with good structural design?

   Joe

1. 
   Guest_ | Nov 09, 1999 03:12am | #3

   *Dear KWJ: If I understand correctly, this shed dormer is going to match and tie into an existing shed dormer on the back of your Cape. So, if the Cape is 40' long, now the shed is going to be 64' long or thereabouts. Sounds like you need basic design help, not just structural. There's more than one way to skin a cat. Find someone local, who know the answers to your questions listed above, who does designs for a living, and make a small investment in your project. It'll be the best and most important money you spend. There are lots of good builders out there, but if your project starts with a plain, utilitarian design, it won't get any better. And please tell me if I got the wrong idea about what you are trying to do. I don't want to get you mad, just get you pointed in the right direction. You can spend the same amount of money working on a beautiful design as you can working on a plain one. One will enhance your pleasure and the value and one will just meet your basic needs.Perhaps your Engineer can recommend a draftsman/designer who has done some nice plans that he has reviewed .

1. 
   Guest_ | Nov 09, 1999 06:11am | #4

   *Mike, I'm trying to figure out how you figured out that the cape is 40' long??? I read the post three times. Also how did you come up with 64' shed dormer???

1. 
   Guest_ | Nov 09, 1999 08:04am | #5

   *Well, I didn't.I had to make some assumptions. 1st, A small Cape would be a 24'deep x 32' long (Half Cape, two windows and a door). A 3/4 Cape would be two windows , a door, and one window. And a Full Cape would be two and a door and two. Around here a Full Cape would be about 28'x 40' And he said that the width was 32' (and that the shed dormer was going to match the shed dormer on the existing part of the house. So , if the width was 32' then the long part had to be at least 40' or it would really be screwed up. Then he said the shed dormer was going to match the existing so I see a 40' Cape with a 40 ' dormer on it and he's going to add another 24' of Dormer to make it 64' . To look attractive, a shed dormer should sit back from the gable ends about three to four feet, the more set-back, usually the better it looks. Or, it ain't like that at all and I'm all wet.Never mind.

2. 
   KWJ | Nov 09, 1999 06:20pm | #6

   *
   Mike - I can appreciate your input. From reading the comments on this page and reading many, many articles, I did use a designer and have drawings built in AutoCAD. The existing house is a half cape, 26 deep x 36 wide. The existing house has a shed dormer which 'sits back' approx. 10' from one side of the house. On the other side of the original structure was a poorly constructed 'car port' (home was built in 1960) with sagging 2x6's spanning 20' and no support in the middle. The space above the carport had been opened up to the house and a closet cobbled on top of the 2x6's. Apparently the weight took its toll over the years and the floor looked like it could fall in any day. The carport has been removed (WIP) and will be replaced by a 2 car garage. With the garage addition, I will gain some space in the front - between the house and the garage door, where a matching window will be added to make a ¾ cape. 2 doghouse dormers will be added to the gable to match the 2 on the existing house. As far as you can tell from an AutoCAD drawing, it looks pretty good. From the rear of the house, the dormer is wide and quite large, but looks acceptable. Using FHB, TOH, HOME, and other mags, plus touring the city of Memphis for 18 months, my wife and I are comfortable with the look. After the drawings were completed, I went to an engineer who recommended the steel beam and a few additional changes in the footers, etc… The engineer is good, but did not give framing specifics for the 2nd story wall supporting the shed rafters. The existing roof of the house does not employ this technique; they tied in 2x4's every 32" from the shed rafter to the 2nd story ceiling. If you would like the AutoCAD file, let me know… It's 1.4mb.
   Commentary: I can't speak for other regions of the country, but in the Southeast the building growth is unbelievable. It took me 2 months to find an engineer that was remotely interested and he does this type of work on the weekends. Electricians, plumbers, concrete contractors cannot handle the amount of new construction in the city and last on their list is remodeling jobs. The man doing my foundation has turned down many opportunities during the year and his crew is working 6, sometimes 7 days a week.

3. 
   Guest_ | Nov 09, 1999 07:16pm | #7

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   Sounds like you gave it your best shot and you can proceed with confidence. Glad I didn't get carried away with snippy comments. Or did I ? I get gun-shy from working on homes that started out with bad design , as you are already the victim of from the addition you're taking off..
   Any how, the strength of the Cape comes from the floor joists tieing the rafters to form triangles. Typically, a 12/12 pitch for the gable (down to as low as 10/12) and the shed dormer usually framing off the ridge at a 4/12 (6/12 looks better if the geometry works out).
   The wall sounds like all it has to do is support the shed rafters.
   The shed rafters should frame to the ridge to thrust against the gable rafters.
   Or they could drop below the ridge and frame to a header.
   You don't need a structural ridge unless you're trying to get a cathedral ceiling.
   If you're using a conventional ceiling, the ceiling joists become the collar ties, and yes you need collar ties unless you have a structural ridge.If any of this is unclear, sketch it out and run it by your engineer one more time so he can confirm your framing plan.
   If you want more help, try one of the web sites like :
   http://www.ChiefArchitect.com go to"Chief Talk" and go to "Seeking Services", There are several Designers there who do designs by Email. You can also try the Chief User's group at egroups.com/chief-users/info.html

1. 
   Guest_ | Nov 09, 1999 07:28pm | #8

   *Here's one you'll really like:http://www.capecod.net/cad/

1. 
   Guest_ | Nov 09, 1999 02:24am | #2

   *Dear KWJ, I've tried to visualize your proposed garage roof and I've been unable to so far. Do you think your engineer is not coming up with good structural design?Joe

4. 
   KWJ | Feb 23, 2000 04:58am | #9

   *
   I am adding a 2-car garage to my Cape Cod style house. The front roof is a gable and the rear a full shed to match the existing roof and provide for future expansion (master bath/bedroom). The dimensions are:
   Front to Back - 32'; Width - 24'. The shed is the entire width of the space. My engineer recommended 24' (W16x36) steel beam, installed on 2 - 3" steel columns, to support 2x10's for the 2nd story floor system. This will support a planned bathroom and the load from a bearing wall in the second story, built on top of the beam. The primary function of the 2nd story wall is to handle the load of the shed rafters. The beam/wall will be in the middle of the space; 16' from the front of the addition. I have a few questions:
   1. Should the wall support both the gable and shed rafters? 2. Should a structural ridge beam be used? 3. Are collar ties needed? 4. Should the shed rafters rest on the wall and continue to a ridge beam where they meet the gable rafters?