Second Storey Addition Options

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Posted by: from Edmonton
10/20/2013 at 12:44:35 AM

We are considering adding a second floor to our home. Before advancing very far into the process I want to determine if it is even possible. Can anybody give me the "standards" used in constructing a home that will give it the strength to support a second floor? We are looking to maintain the entire footprint of the main-floor as it was previously renovated (kitchen, hardwood, etc).

In addition, based on initial quotes coming back there are 2 methods being proposed: (1) Remove the entire ceiling structure (drywall, etc). There is impact to the main floor which requires protection of existing assets (i.e., kitchen cabinets, hardwood floors, etc).

(2) Raise the new floor 1 on the perimeter and center and install the new floor beside the old ceilings without disturbing them. This would leave the existing ceiling intact where possible.

Please advise whether method (2) would work as it doesn't remove the entire ceiling structure and is more economical.

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Design Concept in Vaughan
Date/Time10/20/2013 at 10:42:31 AM

I would have to assess how your house is build. But I dont see any reason why not.


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Norman in Vancouver
Date/Time10/20/2013 at 11:12:33 AM

I have done both options over the years ( +30 ). The most cost effective has been the 2nd option. Typically I will add 2 plates in between the existing roof joists to raise the new floor joists 3" above the existing ceiling below and 'sister them' to the existing ceiling joists where possible then apply the 2nd floor Plywood. With any luck you should be able to rely on the center wall support to be used again to support the new floor.

Best of luck....

Norm Little

CEO - Precision Way Projects Ltd.

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Date/Time10/20/2013 at 4:02:37 PM

Hi Wilson,

I to have used both methods for second and third floor additions. Befor we even get into the a or b. Lets confirm that the existing inside walls have the proper placement and are structurally sound enough to carry the proposed load. I have in the past had to beaf up the inside walls. In some cases add laminated beams in others add structural pillars. Get proper engineering drawings and be sure the house is inspected with the engineer and your contractor together. What about you hot and cold air runs? The list goes on. But you need a ballanced system to work properly.

But lets assume your good to go.

You are going to have to protect everything on the main floor regardless. Aside from all of the mess and costruction dusts. If you get a heavy rain regardless of which option you choose, you could have trouble. If the old cieling structure and the drywall and plaster within get soaked its a mess. We always heavily tarp our projects, as do all good contractors, but nature sneaks up and bites us sometimes.

With a contract such as this if you can do it, its better to store your belongings for a few weeks and live with some family members untill the real nasty parts are complete.

I have had some great clients that put up with the mess, the noise. Power off and on. Water off and on in the Mississauga Road area over the years, but a few have agreed it would have been easier on them had they moved out for three to four weeks.

I prefer brand new construction.

The size and basic shape of your home also come into play. If your home is 1,100 to 1,700 sq feet and basically square or slightly rectangular it is simpler. Many of my second floor additions have been on bungalows that were 3,000 sq' plus. And L-shaped. If your home is smaller, it is easier.

Good luck.

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Wilson in Edmonton
Date/Time10/20/2013 at 11:11:14 PM

Thanks to all who have given feedback.

Our house is a 1700 sq ft ranch style bungalow (rectangular).

Also would you recommend that winter is the best time to do this as rain damage would be minimized?

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Date/Time10/22/2013 at 11:06:39 AM

People always put the cart before the horse. You need to check with your municipal development office and get "a development permit". You cannot build anything without permission!! Permits will also cost about $500-$1,000 and must be accompanied by plans (another cost). Then if it is granted you can build anything you want. It all comes down to time and money.

On average expect from $150-$250/sqft.min. for an addition. Whether you do it or not depends on how valuable your property is now and in the future. Dropping $300,000 on a remodel might not make sense as just buying a new house etc.

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Date/Time10/22/2013 at 10:36:24 PM

After reading the other responses I need to clarify construction techniques. 1st you need to get the upper plans "engineered to even get a building permit", which is required after the development permit. A 2nd story must be built with proper floor joist 2x10 or I-joists and must meet all structural requirements for a load bearing structure including likely beams on main floor. Changing the main floor a little and definetly involving some access to main ceiling structural, not to mention all the plumbing and wiring which has to now go up from basement to 2nd story!! You can usually only do a proper reno on a full 2nd story replace by removing the existing roof etc.

I cannot stress how disruptive this process will be if you try to live in it and if done in winter will cost more as open areas need awnings and heated...better to do in summer, expect from 3-5 months. I always recommend clients move out during the reno. If you have to stay it will be very uncomfortable so expect this and be patient with your contractor who has the added responsibility of having to deal with your family in a major construction zone for several months.

Also personally if I have to work over your new kitchen reno on a major 2nd floor addition I of course would protect it as much as I can but by contract will not be liable for accidental damages, it is impossible to not have some scuffs etc. On a large rebuild like that, it would have been better to do your main floor renos after the 2nd story or consecutive with addition.

Hire people who know what they are doing and expect to pay industry prices to get it done right.


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Mark from CMJ Renovations in Oakville
Date/Time10/26/2013 at 9:36:58 AM

Hi Wilson,

I believe your original question was which is the better method 1 or 2. Option 2 will be the cheapest and will have the least amount of impact on your lives. You may look at the header sizes of your existing windows. May need to be beefed up from 2x8 to 2x10 to support loab above.

Good luck and build in the winter months, less rain.

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