The roof framing has to be designed for the difference. So, to alter the present design, you will have to remove the old roof; framing and ceiling; and install new framing designed for the cathedral ceiling.

Rather expensive.

There are many variables and things to consider,such as moving electrical,any hvac ducting,possible overhead plumbing lines,etc.

Depending on your existing roof framing, you might not have to remove your existing rafters,sheathing,roofing, but your first step would be to hire the services of a licensed structural engineer and get their take on it.

This is something that you will probably be wise to get permitted as well if required in your area.If required and you dont permit, it could come back to bite you should you decide to sell.As handy pointed out,this will be an expensive project that no one here can realy even give you a ballpark on, unless someone out there has taken on a similar project. Even at that, every project has it's own ordeals depending on whats going on in the attic.

We had it done, but there were specific circumstances involved:

1) It was a traditionally framed, 1940's cottage that we were completing gutting and rebuilding. It needed new everything, including a new roof. Therefore, it was only a bit extra to pop up the ceilings over the main area (kitchen, DR, LR). We kept the traditional ceiling over the one bedroom and bathroom on that floor.

2) It's my understanding that a lot of newer construction is done with roof trusses. These can't be re-engineered out without a great deal of expense, which is usually not worth it.

You would definitely want to obtain a permit for this project; if not done correctly you could be creating major structural problems, as well as the resale issue (here in CA, buyers must swear that all work done was properly permitted). I will say that in our small cottage, it made a HUGE difference, altho for us the effect mostly impacted the kitchen and dining room.

Br aware that unless your house is insulated, there is also the issue of heating/cooling what can be a substantially larger room, volume-wise.

jkom51 makes a good point that i left out about trusses. If you have them,(if you have an attic access, you can check yourself),this would involve replacing the whole top end.Along with all the other variables, this would be pricy and risky if you are in wet country.

If not trussed, i would still get the advise of an engineer, or reputable builder to give you an experienced opinion. You should have an attic access located somewhere. They are mandatory here and are generally located in a closet.If no access, you will have to make one temporary or permanent,of your choice.

I did a half vauted ceiling in my master bedroom that created a graduatingly raised ceiling from 8 feet to 12 feet in a single story home with a pitched room. It was done with a licensed contractor in a permitted remodel here in CA. That portion of the remodel/addition cost ca. $7K and was worth every penny. It makes all the difference in the world in a 13 by 15 foot room that now looks twice the size. Money very well spent. I don't know exactly what was involved, but the word trusses was thrown around quite a bit, and I saw a lot of wood being added. Another contractor had offered to do it for less, but without permits.

We raised the ceiling in our family room, and we are very pleased with the result!

We did NOT have to remove the roof.

We tore out the ceiling and had the carpenter 'scissor' the joists (at least, that's what he said he was doing!). He then covered the new joists with boards, upon which we installed tongue and groove oak planks. There are several sets of recessed lighting and a ceiling fan.

I really don't have a price, as the entire family room was gutted, rewired, etc at the same time.

But we are very happy it was done; the cathedral adds a lot to the room.... much better than a large flat expanse of ceiling.

We combined three rooms into one and replaced all the old 7 and 8-foot ceilings with a cathedral ceiling. It was a major undertaking, involving putting in a 40-foot glu-lam ridge beam, along with posts and concrete footings below, new 2x10 rafters sistered on to the old ones, a ridge vent, a radiant barrier and a vapor barrier, spray-in foam insulation, durorock drywall, and tongue-and-groove western red cedar. Materials alone were pushing $8,000. My crew and I did all the work in our "spare" time, but I'd estimate we'd charge at least $20k for the labor, and probably more (didn't keep track of it that well). We did get a permit for it, and a structural engineer signed off on my calculations and design.

It is absolutely stunning, if I do say so myself.

I would like to do the opposite of the OP. The house we are thinking of purchasing has a vaulted ceiling in the living room with two skylights. I would like to change this to a tray ceiling without skylights. Any thoughts as to how this would be done/cost?

Much easier and cheaper going that way, Hawkeye. You'll need to strip off the existing drywall or plaster, put in framing for the new ceiling, nailed or screwed (I really like the 1/4-inch Simpson strong-drive screws for this kind of work) to the existing rafters, then drywall over it. Since you already have the support such that you do not need any ceiling joists to prevent the walls from tipping out, it would be less than a quarter the cost of going from flat or tray to cathedral.

Hawkeye, please let me know how your project goes. I want to tray our way high mb ceiling - makes our room too cold in winter/hot in summer

We're in process of a major remodeling of our 50 yr old single-story, gable-roofed house. Master bedroom was 11'x15'; we doubled the size to 22'x15 and converted ceiling to vaulted. We used a 22+ foot glu-lam ridge beam and 2x6 rafters to support the roof. The vaulted ceiling, also 2x6's, is attached to bottom of beam leaving just enough space between rafters and ceiling joists for hvac ducts on either side of ridgebeam. Ceiling height under the beam is 12ft.

The room has 3 double hung windows and a 5' french door that opens onto a small patio on the back of the house.

For ventilation we replaced a gable vent with continuous strip metal soffit vent and ridge vent. No skylights but we did use a 24" round window in the gable end.

Don't have the costs for this part of the construction separate from the whole. Should be a nice room when we're finished.

It can be inexpensive. The key factor is can the ceiling joist be removed without compromising structure integrity. If so...

1. Remove the drywall.
2. Remove the ceiling joist.
3. Install rafter tie boards across each pair of rafters.
4. Increase the size of the rafters for insulation baffles and insulation.
5. Frame and install the skylights.
6. Redo the wiring.
7. Hang new drywall.
8. And paint.

Moegaff! What do you think?

Phillip

Wow---remodeler08, you make it sound so simple! I hope it can be that easy!! I'll let you know what the GC writes up for an estimate. The great thing is, there is no HVAC ducts or wiring or plumbing in the ceiling to move so that should make it a bit easier I would think?

If the existing roof framing meets the current building code for size and spacing of simple rafters (not trusses) then you only have to provide "rafter ties" (as prescribed by the code) between the rafters at the top plate of the wall and no engineer is needed. The original attic joists may serve this purpose without modification.

If this amount of ties is unattractive in the ceiling (it probably will be) then you will need to add a beam at the ridge to support the rafters and allow the deletion of the rafter ties. That beam and its supports and foundations will need to be designed by an engineer.

Raising the rafter ties is sometimes possible but it is highly unlikely that the existing rafters are sized large enough to allow this.

Mightyanvil's response raises a terminology question for me:

Are attic joists the same as rafter ties? Just curious. I'm going to be helping a contractor friend with a job soon where an engineer did OK the raising of the ties, but I don't know the details.

A neighbor raised their ceiling and to do so they went from 2x4 rafters to 2x10's, thus lowering the wall height at the top plate. I don't know how they attached the new 2x10's to the walls. Nor do I know how the new 2x10's were connected at the peak, though it was an engineered solution. Sorry I can't be more definitive.

Thanks,
Bill

No. Attic joists are what you walk/crawl on while in the attic. Rafters are what holds the roof plywood and shingles. A rafter tie is usually a short 2 x 4 board that is nailed across a pair of rafters.

The smallest "legal" rafter is 2 x 6 in size.

In many cases, the ceiling joists you need to cut out are part of a larger span that leads to another room. In this case you need to face the cut ends with a double header of the same dimension lumber, around the opening. If the width of the opening perpendicular to the run of ceiling joists is greater than 12 feet, you should place a laminated 8x8 truss in the center of the room parallel to the joist run and secure it to the double headers on each end of the room. The truss could be made with 2 pieces of same dimension lumber and boxed in with pine boards.

As an addendum to what I posted above, you may be able to use the removed ceiling joists to make the double headers and truss, thus saving a substantial amount of money!

To answer the question about terminology:

Ceiling joists or attic floor joists are often the same as "rafter ties" because rafter ties are required by code to be in the bottom 1/3 of the rafters to tie the bottoms of the rafters (or the tops of the walls) together so they don't spread apart under the loading of the sloping rafters.

What remodeler08 was describing is a "collar tie" that occurs in the top 1/3 of the rafters and helps to keep the rafters from lifting and separating. They also help to prevent sagging of weak rafters but they do nothing for wall spreading.

When you remove attic floor joists you are removing the code required "rafter ties" and any "collar ties" would be too high up to act as a substitute. Without the rafter ties/floor joists, eventually the tops of the exterior walls will spread and the ridge will sag requiring a very expensive repair.

Trusses will not provide much of a cathedral ceiling. What you need is a beam at the ridge with posts to support the ends all the way to the foundation or a suitable transfer beam. Then the attic joists can be removed.

Raising the rafter ties to about the 1/3 point of the rafters will work for a tray ceiling if the rafters are strong enough to take the additional bending force. That information is in the notes of the IRC code tables so you don't need an engineer. However, for all but very small houses the rafters quickly need to be 2x12's and the connections need be bolts and you should use an engineer.

Moegaff, you've received just about all the advice that there is to give about your situation. Your best course of action is to get an experienced structural engineer or architect to look at your specific situation, do necessary calculations and give you a design that will work and meet the building code. Good luck!

Moegaff asked the question over 5 years ago so I hope he/she isn't still waiting for advice.

So the question still remains, and I challenge for an answer. WHAT ARE THE CREATIVE, TASTEFUL, AND DARE I SAY BEAUTIFUL WAYS OF SURING UP THE FOUR WALLS? It has been established that collar ties are needed in the upper portion of the roof rafters but what additional support (that looks good) can really be put in place so that the ceiling joists can be removed. Also, the catch all "call a structural engineer" I find to be a brush off. It seems like that individual would just through one more opinion in the pot and say what he/she THINKS will hold. What calculation do they really make? And how ?

Your question has already been answered.

The existing ceiling joists act as rafter ties and are required by the building code and "accepted engineering practice". If you remove them the only remedy is to install a beam spanning the space and supporting the tops of the rafters. This beam removes the horizontal component of the rafter load so rafter ties are not required. Collar ties serve a different function and are of no consequence in this design.

Such a beam cannot be sized by the residential building code prescriptive tables so it must be designed by an engineer in all but a very few jurisdictions.

How the engineer sizes such a beam is not a matter of opinion; it is done using the procedures of "acceptable engineering practice" as required by the building code and taught in all engineering schools. As an architect I can design the beam as well as an engineer can but I cannot stamp it for a permit. However, you can get an LVL supplier to design and stamp it through a lumberyard for free.

The primary design problem is how to provide support to the ends of the new beam so it is transferred all the way down to the ground with a proper foundation.

Propertyfarmer didn't like the answer.

You really don't need the advise of a structural engineer.

Just go ahead and do it based on what somebody advises you to do from an internet forum. Let us know how it turned out, you just might get lucky.

According to the International Residential Code any project that involves a structural element or life safety requires a building permit and drawings stamped by a licensed professional engineer or architect. (in NYS)

@PMH - LOLOLOLOL

https://www.designevolutions.com/blog/house-plans-questions/does-my-state-require-house-plans-to-be-stamped-by-a-licensed-architect/