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HomeMy WebLinkAbout04120060 Correspondence Too Dept. of Community Services, Cijy of Carmel From: Victor Luling Date: 12/9/2004 Reo: Ceiling remodel Building Permij Application In addijion to the Building Permij Application and required attachments I've also included an article from Fine Homebuilding describing the framing construction of a soffillcoffered ceiling. I used this article to help me understand and plan the project. I designed my Framing Plan using the one included in this article. Of particular notice are the 10" double-plated ceiling joists. I would like to use this framing technique for the soffrt and not provide any addijional support for the coffer ceiling box other then the hip and common railers. I checked spanning requirements for sag on 10" joists made of southem pine #1 and the maximum span (in my case, approximately 12) is within the specifications I found. I didnt check Indiana joist span requiremerrts but I'm hopeful that my project requirements fall within Indiana specifications. One other ijem, the height of the coffer ceiling box may not end up being exactly 2 II from the ceiling line, with 45-<1egree pijch. The roof railer pijch on the south side of the house is pretty gradual to an off-center ridgeboard. There's not a lot of room to work with in the attic on the south side. What I've designed is my hoped for height but I may have to lower ij to allow for the roof railers. Thanks for your consideration on this project. ED FOR CONSTRUCTION RELEAS Iiance with all regulations Subject to comp 01 State and Local Codes. ci'~6~6fR~~~~~Y ~;0~;~\P INDIANA ~ ~ L~ Vielor Luling 3609 Walden Place Carmel, IN 46033 844-1457 .' Building Coffered Ceilings Three framing methods Editors note: The following three projects hardly look the same, but they share one detail: a coffered ceiling. A coffer is characterized by sunken panels (they're usually square or octagonal) that decorate a ceiling or a vault. Though the term is generally associated with multiple panels, a proper coffer can have a single panel. The tech- .nique is thought to derive from the visual effect created in buildings where heavy ceiling beams crossed one another, and it has been used structurally and decoratively for buildings as dissimilar as neo classical churches and the Washington, D. c., subway system. Don Dunkley frames coffelS into custom homes, typically by cre ating one big recessed panel. Greg Lawrence used coffering to con ceal glulam beams. And Jay Thomsen used crisscrossed Ix wood strips to create the effect of sunken panels over the surface of a vault. ed ceiling. -Mark Feirer, editor of Fine Homebuilding. Orui Irig eofflw. Soffits gJrdIe ibis bedroom 10 support angled coffer framing. A single, receaoed celIing coffer is the resulL Photo by Scol ZImmerman. 122 The BeAt of Fine Homebuilding Single Coffer by Don Dunkley Among the most common ceiling details I run into when framing custom homes is the coffered ceiling. Though the tenn coffer encompasses a range of ceiling treatments, around here we use it to refer to a ceiling with a perimeter soffit hav- ing a sloped inner face that rises to a flat ceiling (photo left). The detail is usually found in bed. rooms and dens. The first coffers I built were usually sloped 10 match the roof and fastened directly to the roof framing. There was no soffit; the sloped portion of the coffer simply died into the surrounding wall. I used this method routinely for a few years-until I realized its limitations. For one thing, linking the roof to the framing of the ceil- ing limited the angle of the coffering to that of the toof (unless a very steep pitch was used on the main roof)_ Also, there Was a limit to the amount of insulation that could be put into the perimeter of the coffered ceiling. Adding a soffit to the coffering solves these problems. The soffit encircles the room and is framed so that its underside is level with the top plate. The soffit usually extends 1 ft. to 2 ft. away from the walls and offers several advantages. Framing is simplified, the pitch of the coffer can be any an- gie, there's plenty of room for insulation, and the flat ceiling surrounding the room can be embe~ fished with can lights and croWn molding. The layout and the pitch of the coffer are usu- ally found on the floor plan or the electrical plan. But before I start framing, I usually confer wilh the builder or the home owner to finalize the actual size of the soffit, the pitch of the coffer and the height of both the main ceiling and the sof. fit. Once these dimensions have been continu- ed, the framing can usually be completed in a few hours. Traditional Coffer by Greg Lawrence In the COUlSe of a recent remodeling project, we re- moved the roof from a 12~. ft. house and buill a second..tory addition in its place. We had to de- molish the vaulted ceiling of the existing living room to make space for the new rooms above. To support those new rooms, we installed several glu. lam beams parallel to the exterior wall; the photo at right and the drawin below show how we cof. fered the ceiling to con althe glulams. First we wrapped each ulam on three sides with Ix Douglas fir, detailing edges with a round. over beading bit and a rou . Then we built inter. secting false beams with 2 blocks (ripped to match the width of the g1ulams d more fir. final- ly, we trimmed the ceiling wit rown molding. Where the molding returned off t window head casing, a striking homed cornice w created. The resulting coffered ceiling a a stately look to the room and nicely campI ents the window muntins. 0 Greg Lawrence is the owner of Green Ri struetion in Sebastopo!, Cali!. Photo by the au It starts with the 8Offit-One of the big advan- tages of the coffering technique I've adopted is that the coffer framing can be done before the rOj'f is constructed. That gives us plenty of room in which to work. The first step is to iay out the lo- cation of the doubled joists, sometimes called camer joists, that tonn the outer edge 01 the soffit (drawing, p. 124). The locations are marked on the top plates of the surrounding wall, the camer joists are oversized because they support both the coffer framing and the soffit framing-we usu- ally use 2xl0s or2xI2s, depending on the size of the room. It's important to build this part of the framing (we call it a carrier box) straight and square. Otherwise, the rest of the coffer will be a bear to build, not to mention what the finish car. penter will say about you when he hangs the crown molding. Nail off all the carrier joists very well because green lumber, while drying, will try to go places you don't want it to visit; three nails spread the width of the boards on l&-in. centers will suffice. Of course, in order to build a good, square carrier box, the surrounding wall framing had best be on the money-a square box in an out-of-square room will endow the soffit with a noticeable deviation in width. To install the carrier box, start by spanning the room (usually, but not always, the shortest di. mension) with doubled carrier joists. Once thffiE have been cut and nailed in place. string a d.r} line across each pair and brace them straight with a temporary 2x4 "finger." Nail the finger te the carrier, push the carrier into line, then nai: off the finger to the underside of the top plate This will hold the carrier in place until the fram ing is complete (top right photo, p. 125). Alte, I ...,._ Idp. Once Ibe 80111t loin pla<e, framing for Ibe roII'er ItBeIf is Uke a hip roof wilb Ibe lop removed. Preaaure blocks are oaDed betweeo from. 'li membera 00 ellber tide of Ibe doubled carrier boX; Ibe blodol prevenl Ibe framing from Iwi8lIng 88 II drlea. M The Best of Flfle Homebuilding lining the first two pairs of carrier joists, measure and hang (we use joist hangers) the second two pairs between them. These carrier joists should be lined and braced as well. With the carrier box in place. you're ready to layout the locations of soffit joists on the top plate. We use 2x4s 16 in. o. c. for these joists, run- ning them perpendicular to all four pailS of cal- rier joists (drawing left). The soffit joists should tie into the rafters at the exterior wall plates (a code requirement in these parts). so lay the rafters out ahead of time. As we toenail the soffit joists to the plate with 8d nails, we secure pressure blocks in every other bay (photo above). A pressure block fits snugly between the ends of the joists to prevent them from twisting as the joists dry. Nail a lx4 to the top of the joists that are toenailed to the plate, running it the length of the wall, and secure it with a pair of 8d nails at every joist. Caned a cat- walk around here. the 1x4 is required by code and helps to prevent twisting at the wall end. It should be located as close as possible to the in- tersection of rafters and joists. One iaat check for clearance-With the soffit lraming in place, you're ready lor the angled col- ter framing-but not before one last check of the specs. If the coffer is at a steeper pitch than the roof framing to follow, now's the time to make sure that the coffer framing won't interfere with the rafters. If someone changes the pitch of the F....mlnll the o:eUlag. A ceiling box with mitered comers (photo above) forms the peri- meter of the ceUlng, A xbort hip railer with beveled plumb cnIll at top and __ ""nneelS the comers of the celUng box to the donbled canter box. roof from what's on the plans, the angle and the height of the coffer should be recalculated-a quick double-check now can avoid major prob- lems later when the root gets framed. To check this, measure the run from the inside of the exterior plate (in most cases, this is where the bottom edge of the ralterwill start its incline) to the inside edge of the carrier box and add this figure to the run of the coffer rafter. This gives the overall run, and by plugging this into a ca~ culator (I use a Construction Master II) and en- tering the pitch of the roof. you 'II end up with the height of the roof rafter's bottom edge. When 6 in. is added to account for the thickness of the ceiling framing, you'll know it the coffer will col- lide with the rafters. II it will, lower the pitch of the coffer. II the ceiling heighl hasn't been given on the framing plans, check a section detail (if there is one), A decent set of plans usually carries ail this infonnation, but not all plans are created equal. If the plans have left this information out, you'n have to calculate the height of the coffer based on the run and pitch of the coffer rafter.;. The coffer tayout- The coller layout is no mys- tery; think of it simpfy as a hip roof with the top cut off (photo facing page). At each comer there will be two common raftelS and a hip rafter; the areas between comers will be fiUed with com- mon rafters. After laying out a common-rafter pattern, we cut as many rafters as we'll need. Mark the locations on the carrier joists of all eight commons that form the coffer comers, then pick one comer and work your way around the box, installing the fill rafters. These are usually 16 in. o. c., but 2 ft. o. c. is fine if the coffer is small. We use either 2x4 or 2x6 stock-in general, we use what we have most of. Of course, an unusually long span might call for larger stock. Armed with the rise and run of the coffer rafters, you can figure them for length (for more on rafter framing, see FHB #]0, pp. 62-69). There's no need to figure in a shortening al- lowance, though. When the length is known, we cut one pattern and then whack out the quantity needed. II we're building more than one coffer of Helplag fintleN. P1ecea of acrap stock, caned fingers, Mould be naDed between the can joists and the surrounding waD framing, They prevent the joists from bowing as the somt from Is lnsIaIled. Later on, the fingers will be removed. I I Bk>eIdntIthe ...-r.. With the framing complete, DunIdey wolks bIs way aronnd the cell1Dl InslaU any /ast p.~" blocb that mJgbl be required. me same SIZe, the second set of rafters can also be cut now. The coffer framing-After the rafters are cut (but before installing them), we build the ceil- ing box at the top of the coffer, which is similar to the carrier box that forms the soffit. The differ- ence is that the ceiling box is smaller (by the run of the coffer rafters), and the lraming is not dou- bled up. We usually lrame it on the deck lrom 2x6 stock, then lift it into approximate position, using temporary leg; to hold it up; these leg; wilL rest on the floor. The frame should be square; caretuLIy cut rafters will keep it straight. Once the ceiling box is up, install a pair of com- mon rafters at each comer to hold the box in place. Toenail the rafters top and bottom, then in- stall the rest of the commons, adding pressure blocks to prevent the rafters from twisting later (bottom photo, p. 125). When installing the rafters, make sure that they're not bowing the ceiling box; trim them if necessary. When the commons are in, cut the hips to fin- ish off the comers (top left photo, p. 125). The hips will have double cheek cuts on both ends; the cuts can be measured in place or calculat- ed. When installing the hips, fit them in SO that the drywall will follow the plane of the rafters into the center 01 the hip. A 6-ft. length of 1x4 makes a good straightedge to guide the hip pLacement. Fill in any jack rafters, if needed. The ceiling framing is simple: Just add joists in- side the ceiling box and fill in between with pres- sure blocks (bottom photo, p. 125). We use 2x4s taid flat to provide backing lor the ceiling dry- wall along the length 01 the ceiLing box. A strong. back can be run down the center of the joist span to prevent the joists form sagging. Variations-There are several variations to our coffer-framing techniques. One way to install the ceiling box is to eliminate the temporary leg; and install eight common rafters at the comers of the soffit. Then lift the ceiling box up past the com- mons until the bottom edge is flush with the bo~ tom of the rafters. The pressure of the commons will hold it until everything's nailed off. Another approach is to nail the ceiling frame to the commons one board at a time, eliminating the need for help in positioning the unit. This box is supported by the hip rafters. It can with- stand quite a load as long as the lower ceiling box is well braced with the ceiling-joist fingers, Crown molding-if crown molding is desired at the top of the coffer ceiling, the ceiling joists are placed on top of the ceiling box, allowing a 5Y~in. recess for Lhe molding. To bLend the bot- tom of the coffer rafters into the inside edge of the recess, we rip the bottom edge of the ceiling box to match the rafter slope, providing a smooth transition. If the rip reduces the width of the stock too much, cut the commons with a notch to ac- commodate the ceiling box so that they will blend into the inside edge (the box will be over- sized by 3 in. to make up for the notch). 0 Don Dunkley is a framing cantractar in Cool, Calif Photos by Charles Miller except where noted. Applied Coffer by Jay Thomsen Usually an addition is built to reflect the design of the main house. A recent project of ours, how~ ever, show that the opposite can also be true: Eventually, e Mrachek's house will be remod- eled to refl the addition. As vice-pr ident of the Handel and Haydn Society in B ton, Massachusetts, Bobbi Mra- chek wanted oom in which to entertain large numbers of gu , usually for live perfonnances of classical musi The design delivered by local architect John M nnell called for a room 40 ft. by 15 It. 16 in., top d with a barrel vauLt. The look of the ceiling h to be bold, but not dark and depressing, and surfaces had to reduce the echo effect of such large space. Coffering would soak up the ech . To do this without further complicating an al dy involved ceiling structure, we created a colf effect with strips of Ix stock (photo faCing p Providing the 8In1cture-As conslructed barrel vaults belor so big. Given the dimensions of e new room, we knew we had a serious proje to contend with. Fortunately, articles by Gerry C land and Lamar Henderson (see pp. 129-135) h quit a bit. We framed the main roof of the add gable with 2xlO rafte... Flush-framed c (photo top right) secured with metal ptates completed the basic shape of th Plywood gussets would form the exact the vault and provide a nail base for e fi ceiling (photo bottom right). Calculating the radius of the pi was done simply by drawing a Iayo to exact scale using a string. a na. Sheets of %-in. CDX plywood w on top of the curve, and the ra on top of the sheets. Three and several jigsaw blades I to begin installation. A working 8Olulloo- height 01 the ceiling (18 ft. 6 in.) became a I or in our planning at this point, not so much r safety reasons but for convenience: To hand ch of the L350 pieces of the ceiling up a tong ader from below would have taken too muc me. So we constructed a temporary second fI r within the room to serve as a work plattor we'd need only a short stepladder to reac he highest point of the ceil- ing. A space 18 in ide, running the length of the room, was Ie along each side of the plat- fonn to provide cess for hoses, cords, passing up stock and e n to dangle our legs through when working the springline of the vault (the springline is t point of the ceiling where the curve first lea the vertical piane of the wall). The IInIsb ceUIng-After screwing the plywood gussets to the rafters and touchjng up the result- ing curves with a belt sander, it was time to start nailing up the Ix6 linish ceiling. The Mracheks didn't want to see the V-2'roov~ thnt WOllin ('h~r_ e the seams of conventional T&G stock. tom stock was milled from clear select Y'ery piece was prestained on both sides h edges-twice-:-before installation and d as soon as it went up. We s ed the first piece of Ix6 at the center- line of tn ceiling. Succeeding boards were then brought wn either side toward th~ springlines. This allo d two crews of two men to work at the same t e. We used nailers and 6d finish nails to secu the boards, toenailing most con- nections to av . d the incredible amount of time it would ave en to fill exposed nail holes with wood p The coffer emerges-The main ribs of the cof- fering were to be layers of ~in. pine applied in descending order of width (drawing, p. 128). Intersecting ribs would overlap each other. Our hnn.:w: u,or", th."t th.... 1.........-:..... ~I ~n_l- ___L.~_