Estimate Cost for Lifting (rebuilding) Roof to Create Attic Space (ceiling remains as-is)

2/12/2019 at 7:53:50 AM

Hello Sonny,

I have completed several additions in the Toronto area without have to remove the exisitinf ceiling.

The cost is difficult to determin without engineering but I would estimate $30-$50k for a unfinished area. Other than minor touch ups where we would place the attic hatch.

2/12/2019 at 10:58:19 AM

Thanks Tino for response and providing a quote.

2/12/2019 at 11:29:50 AM

Hi there.......Without an engeneered dwawing and approved permit It is hard to determine a cost......Could be as high as $50,000.00

Several questions come to mind.......

Stairway or attic hatch

You need some lights up there

Trusses are not practical because of

engineered cross members.

A mansard roof could be the

answer.......6 feet high, with 3/12

trusses on top.

Plumbing stack has to be

extended.......Same with exhaust fans

etc..

Sometimes damage to ceilins is

unavoidable.

If you put a plywood floor on top, the

amount of ceiling/attic insulation is

limited to the height of the ceiling

joists, unless you frame "sleepers" on

top.

Hope this helps and does not create more confusion.

Regards,

Gerard Schoeman

Betterbuilt(2525)

2/12/2019 at 1:34:04 PM

Thanks Gerard for your response and, no, you totally did not confuse but provided valuable additional points for consideration!

Yes, lighting will be required. Besides, there are soffit lighting currently which will require electrical work to move them up to be with the new ceiling.

And, yes, plumbing stack will need to be extended and there are also 2 brick chimneys (now being used for PVC intake/exhaust pipes for gas fireplaces) which will need to be extended as well.

We are okay with having two attic hatches i.e. one on either side of the house (one inside the walk-in closet and another in the garage). We'll need to talk to architect or engineer as we are not sure what is the implication of having stairs going to the attic as we'd not like this attic space be added to our living space for property tax purposes. For now, (Q#1) if you happen to know that attic with a staircase will not result in attic space being added to living space calculation then we may consider staircase otherwise attic hatch with a folding staircase that comes down as and when needed should suffice.

Last point, regarding damage to ceiling, you mentioned that a plywood could be nailed to the attic floor. (Q#2) Could this be done as the existing roof/frame is being removed/dismantled to prevent ceiling damage? Our ideal case scenario is to be able to live in the house during renovation as well as not have any ceiling damage (e.g. we could be out of the house during the daytime for a few days but we are hoping not to have to rent a place to live during renovation). If that means we have to have sleepers for insulation then that would be acceptable.

2/12/2019 at 1:54:38 PM

Hello,

I'll try and answer as best as I can.

Since your house is 1950, it is more than likely "rafters" and not "trusses", but you should know the differences as your "new roof structure" is going to have to be decided on between these two by you & your general contractor. There will be pros/cons to each. This is going to be very difficult to evaluate for price since we don't have plans on the current/new roof structure. This kind of job is prone to not being practical in terms of budget, especially if you just want storage but if you really want to find out, you will have to risk revision after revision to get a plan that a contractor will feel comfortable implementing without having to charge you double for risks. I'd say you might even want to just get two complete 'options" plans and get bids on both.

1) Feasible = probably not if you care about a budget. Cost could be 1/5 to 1/4 of your home value as a guess but it's not necessarily the work that makes it expensive. There's going to be engineering, architect/designer huge costs as well and if you want to have your roof put on quickly for weather purposes, you might need to prefab it on the ground and crane it into place. The demo of the old one is going to have to be done layer by layer/piece by piece in reverse building order for safety reasons. A quote for example will probably be double what the actual costs are and this is a job only a handful of contractors can actually do properly & safely. It's too bad you've already completed interior renovations because there might need to temporary bracing down to your floors to keep your walls from deflecting too. You're probably going to have cracks in your ceiling and some doors may not close properly.

A mansard roof is going to be even more expensive. #3) below will add costs too.

2) The time schedule for work will be hard to guess because you have two options and your contractor needs to see details. One way is faster than the other but that involves a crane. Planning and permitting is going to take 6 months I'd guess but then again I've waited on engineers for 3 months.

3) Hoarding for rain will need to be done OR that could be saved as a mitigation plan if you decided to crane the new roof on during a dry period.

4) Nobody should be living in the house OR be in the house except for experienced workers during the roof demo & reconstruct as all sorts of stuff can go wrong. Remember your ceiling joists are under tension. There could be a lot that can be done however while you're living in the house such as removing the shingles or building the "new roof" on the ground for example.

5) The kind of contractor you're looking for is somewhat rare. You want a general contractor for renovations but more than just that. These sorts of jobs aren't common and finding one with experience is going to be difficult but not necessarily mandatory. Any renovations contractor that does vault conversions are going to have an edge. Make sure there's insurance and liability.

Another note, this reno could trigger bringing aspects of your house to new building code and extra costs may be incured simply because your jurisdiction will require you to make the changes. Insulation for example.

My advice, choose an addition instead, vault your ceiling for style if you want. Adds sq. ft. and you get better value & ROI.

Cheers

2/12/2019 at 5:09:23 PM

Hi Justin, thanks for taking time and responding in such detail. Even though your points are very clear, and didn't leave any doubt, I'd still like to respond to them as an acknowledgement for you kindly taking the time out to respond as well as for posterity (for the other readers as we did not find much information on Internet about this).

Actually, yes, although the house is old but the roof has trusses. So, based on what you said, it means the previous owners must have replaced the roof more recently.

Based on what you said about multiple plan revisions required, perhaps we should look for a contractor who works with architects/engineers directly. Your suggestion about finding someone who has done vault conversion is well taken. Btw, vault conversion may not be a suitable option for us as it will make our project extremely expensive (we have high end ceiling work done already, fortunately or unfortunately) while it would not provide for additional storage which is our objective.

(1) Regarding damage to rest of the house. Yes, we'll need to evaluate that with engineer and contractor.

(2, 4) Schedule can take as long as needed but we'd like to minimize the time we'll have stay out of the house.

(3) We didn't know that new roof can be craned for our purposes (we have seen flat roofs craned but, yes, same principle could apply here). Regardless, either of these, or some plan, will required to prevent rain damage

(5) Point well taken, I'll obviously start with pros here.

Lastly, yes, we have looked into additions already. However, lifting roof seems more attractive i.e. as long we the potential risk to remaining structure is minimized.