This is one of the most common questions homeowners ask when considering a siding replacement. The short answer is: you should always remove your old siding before installing new. While installing over existing siding might seem like a way to save time and money, the risks and long-term consequences far outweigh the initial benefits.
Reasons to Keep Old Siding
The only compelling reasons to leave old siding on are typically related to a lower upfront cost and a faster installation.
Lower Upfront Cost
By skipping the tear-off process, you avoid the labor cost of removing and disposing of the old material. For some homeowners, this can make the difference in being able to afford a new siding project. However, these savings are often offset by higher long-term costs.
Faster Installation
A contractor can start installing the new siding immediately, which can cut the project timeline down by a day or two. This is particularly appealing if you have a tight schedule or are trying to get the job done before a change in season.
Risks of Leaving Old Siding
The risks of leaving old siding in place are significant and can lead to costly problems down the road. This is why most reputable contractors will not offer to install new siding over old.
Hidden Water Damage
The biggest risk of all is hidden water damage. Your existing siding may look fine on the outside, but underneath, you could have rotting sheathing or framing that has gone unnoticed for years. Installing new siding over this will trap the moisture, accelerating the rot and creating a perfect environment for mold and mildew. This is a recipe for a catastrophic structural failure down the road.
Weight and Ventilation Issues
Most homes are not built to bear the weight of multiple layers of siding. This added weight can put a strain on your home’s structure. Furthermore, improper ventilation can cause moisture to build up in the walls, leading to mold and mildew. Proper house wrap and ventilation are key to a healthy home, and these can’t be done correctly if the old siding is not removed.
Benefits of Removing Old Siding
Removing the old siding provides a fresh start, allowing for a better, more durable installation.
Clean Surface and Better Warranties
When you remove the old siding, you get a clean, flat surface to work with. This ensures the new siding lays perfectly flat, creating a flawless and aesthetically pleasing finish. This also gives the installer an opportunity to properly apply a new house wrap, which is essential for weather and water resistance. Most siding manufacturers’ warranties will not cover an installation done over existing siding.
Opportunity to Add Insulation
A siding replacement is the perfect time to upgrade your home’s energy efficiency. Once the old siding is removed, you can easily add rigid foam insulation or an insulating house wrap directly to the sheathing. This can significantly improve your home’s R-value, leading to a more comfortable interior and lower energy bills.
Decision Factors for Homeowners
While the recommendation is always to remove the old siding, here are the key factors you should consider.
Age and Condition of Existing Siding
If your existing siding is old, warped, or showing signs of water damage, it must be removed. If it’s a very thin material and in near-perfect condition, you might be able to get away with it, but you’re still taking a significant risk.
Budget and Resale Value
The small amount you save upfront by not removing the old siding will be lost if you run into major structural problems later. Furthermore, a professional installation that includes a full tear-off and a clean finish will add more resale value to your home and make it more appealing to potential buyers.
FAQs
Can I install vinyl over asbestos siding?
No. Never install siding over asbestos siding. Asbestos is a hazardous material that needs to be handled and removed by a licensed professional. Disturbing it can release dangerous fibers into the air, putting you and your family at risk.
Does removing old siding cost more?
Yes, the labor and disposal costs of a tear-off will add to the total price. However, this is a necessary expense for a proper installation and long-term peace of mind.
While it may be tempting to cut corners, removing your old siding is a crucial step for a professional and long-lasting siding project. Ready to get started on your home’s exterior? Contact Greater Boston Contractors today for a free estimate and a professional consultation.