When replacing siding start with a clean slate

Hey there, time traveller!
This article was published 21/03/2015 (4042 days ago), so information in it may no longer be current.

Question: I read an article you wrote on the Internet and it prompted me to ask about a new siding project on our home we are planning. The house still has the old cedar lap siding, which has become a bear to upkeep with paint and caulk and so much of it is rotten. A number of years ago we had all the windows replaced. I’ve done some research and have been impressed so far with the LP SmartSide product. It looks good, is easier to install than fiber cement, and it’s not cheap looking like vinyl siding and lasts longer. Currently the house has only the siding, no sheathing, blown in cellulose insulation, which we did 26 years ago, because there was no insulation at all. On the inside, most of the walls are plaster with a gazillion layers of paint. That’s it, cedar siding, studs, drywall.

What is your professional opinion of the Smart Side product compared to others like cement board or vinyl or real wood again? Also, what is the process for this old house? From what I have researched, the way to do this project would be to remove all the old siding, put in new insulation batts, plywood sheathing, house wrap, then lathe strips for air space for the siding. Would this help prevent moisture problems? For this process I assume a vapor barrier cannot be put in unless you removed all the interior walls?

I’m really doing my research because we’ve had several siding “experts” give us estimates, most are saying that they just put the siding up over the old stuff and then beef up the widow trim and wrap with aluminum. I’m not buying into that. Seems like it’s putting a Band-Aid over a major cut needing stitches.

Thank you so much in advance for your advice, Deborah Blackwell, Wisconsin

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We have a house that was built in 1962 and we are looking at putting siding on. We got a quote from a company, but they want to remove the original wood siding before they put the new siding on and the quote is quite high. I just want to know what your thoughts are on this, as a lot of companies just put the vinyl siding over the existing wood siding?

Thanks, Marilyn Neumann

 

Answer: When wondering about whether to go the extra mile during renovations or upgrades, you should always err on the side of a little more, rather than a little less. As the often overused saying goes, “do it once, do it right”.

Choosing a product to use for retro-fit siding on an existing home can be a slightly daunting task, due to the numerous options available. I’m afraid that I am not at all familiar with the product in the first inquiry, so further research may be required before settling on it. The main thing to explore are the long-term results of previous customers who have used this product. How long has it been in use, particularly in a cold climate location like Wisconsin? Has it held up well to the snow, cold, and heavy rain that may be normal environmental conditions in your area? This information is critical because a lot of building products may be developed and successfully used in moderate climates, but will not do well with the extremes in temperature and humidity fluctuations in our northern areas.

As far as the methods that should be employed to replace the existing siding on the homes in both submissions, more is better. While it may be possible to install new siding over top of older layers, it is not advisable for several reason. Firstly, the older wood siding may have a fair bit of wood rot or decay that may be hidden. This will continue to occur if it is covered with another layer of siding, which may even promote quicker deterioration due to the lack of fresh air and sun for drying. Also, removing the older layers of siding will allow a good inspection of the sheathing beneath. This is important to see if moisture has penetrated the siding layer, causing damage to the sheathing or framing. With the siding off, any damaged sheathing may be easily replaced. Going to the sheathing level will also allow removal of any older building paper that may also be damaged, and allow easy installation of new paper or housewrap under the new siding.

Removing older siding may also allow for improvements in the thermal protection of the existing exterior walls. Because older homes often have minimal insulation in the walls, removing the wood siding should allow easy access for removing the old sheathing and insulating the wall cavities from the outside. This will allow for a high quality job, without major disruption inside. It will add a significant cost to the job, especially replacing all the sheathing, but may be well worth the effort. Alternatively, rigid insulation can often be installed over top of the existing sheathing on the exterior, prior to the new siding layer. Either of these methods should improve comfort and energy conservation levels within the homes.

The final consideration are the windows and doors. Installation of an additional layer of siding over the old will add thickness to the exterior walls. This will normally require building up all the door and window frames or brick moulds. That can add quite a bit of time and cost to the job, so removal of older siding and replacement with a product roughly the same thickness may negate the need for this additional work.

While it may be possible to save some time and money when upgrading older siding on a home by going over top of the existing, it is not a smart choice. Removing the older siding to accommodate the new material will do a better job, possibly preventing costly extensions on the window frames, as well as improvements to the insulation. When doing home renovations going that extra step is almost always the right approach.

 

Ari Marantz is the owner of Trained Eye Home Inspection Ltd. and the past president of the Canadian Association of Home & Property Inspectors — Manitoba (cahpi.mb.ca). Questions can be emailed to the address below. Ari can be reached at 204-291-5358 or check out his website at trainedeye.ca.

trainedeye@iname.com