Do I need to remove all the previous siding before installing new Vinyl siding? why?

Question

Hi,

I want to install new vinyl siding on my house, and I have got some quotes from different contractors However some have said that it is better to remove all of the old layers of different siding on the house and some have said just to remove the first layer that's aluminum siding and leave the layer under in place.....nobody offered and explanation as to why I should remove them all the contractor who sudgested to leave the older layers said that it was better for insulation.....is that true? what's the right thing to do and why ?

Answer 1

need a flat level surface to nail the siding to....if not then the new siding is not going to look good all wavy

Answer 2

I agree with the first answer.  Also, the more layers you have, the more recessed your door and window trim is going to look, unless you replace the trim and furr them out.  (but be sure that they are flashed correctly)

Answer 3

I had old slate siding on my house, I shuddered at the thought of removing all of it, being handi-capped and, by myself. I knew from being retired in the "business" it wasn't that necessary to remove it, just make sure all areas are flat and, even.

       I had to put in a few sheets of cheap plywood to make sure of this, then proceeded to put on the siding. It;s been on for five years now without any problems. If you have any questions ask Home Depot, they have specialists there to answer you.

Answer 4

I have some experience with this. It really is a personal choice, and sometimes what is cost effective is better. But, I am going to assume from what you have told us that you have a house that was originally cedar siding, then it was wrapped with aluminum, and now you plan to put on vinyl. Whenever replacing siding it is very important to remove all previous layers and get all the way to the actual sheathing of your house. Sheathing rots and gets damaged over time and you can never have any idea of the problems underneath the original siding unless you strip it. If you simply cover it up with new vinyl siding it will only compound any problems with mold/rot that may be lurking underneath. The vinyl siding will create a cavity over the old siding where there is room for air and temperature differences that will make the vinyl siding more prone to warping over time, and that is on top of the fact that without the flat surface of the actual sheathing, it is more difficult to install the vinyl perfectly flat. My neighbor installs Certainteed vinyl siding on houses and ALWAYS removes old siding because even though it may cost more, the benefits to the consumer far outweigh the costs of having totally hidden problems or having to have workers come back out to fix things.

As far as them telling you its better for insulation, thats not entirely true. Tearing down the old siding allows them to replace the Tyvek, repair any rotted out plywood and get a better seal around windows and doors where the most air is leaked in any house. So I'm not sure how true that is, sounds like a crock to me.

Answer 5

What you need to know is what the condition of the old siding that you are covering is first. Best to make sure there is not any rot or termite damage in the old siding. The gain from leaving the old siding is usually minimal at best, I mean its old and was not built with insulation as its primary design.

You can have sheets of foam installed over the old siding, up to a r3 rating.

It has been my experience that removing the old siding gives a better finish to the windows and doors.

Some contractors are just a little bit lazy, huh.

Answer 6

Whether or not you remove the old siding is usually simply a matter of personal choice.  As long as there is no rot around the windows or doors, soffits, fascias, or the old siding itself, there is absolutely nothing wrong with leaving the old cladding intact.  There is something to be said for whatever thermal mass you can retain, and old siding has thermal mass.  Definitely, it is advisable to opt for the R3 foam insulation.  

What you want to make sure of is that the vinyl siding is installed properly, and doing so is not as simple as it appears.  Some things to monitor include:

1) When installing the siding, nails should NOT be driven too fast to the surface.  Mashing the siding's nailing surface hard against the old siding will cause 'ripples', as the new siding will not set evenly into the 'locking' channel.  If installed haphazardly in this manner, it will also be easier for wind to get under the siding and pop it loose from its channel.

2) Watch for poorly cut pieces around windows.  Cut too short, and wind or water can get behind the siding.  You won't notice any water issues until it becomes an expensive proposition.  Cut too long, the siding will be visibly 'warped'.

3) Flashing and overlay around windows needs to be done carefully.  If this is not done properly, you WILL have moisture problems at some time in the future.

Often, people want to install vinyl siding to cover up rot, and to avoid expensive replacement of already-damaged wood.  This is a mistake.  If you have rotted wood, you have moisture problems---that's what caused the wood to rot in the first place.  If this is the case, you really need to have the extent of the damage assessed before you consider covering anything up.  If you're just tired of painting, and the most damage you have is some peeling paint, then I'd say...opt for the R3 foam, and cover it up!  After all, you know what they say..."Vinyl is Final!"