You’re in the position where your home needs a makeover, but you don’t know where to start – the insulation or other home improvements.
The home improvement project you are planning will determine what to do first, whether it’s foam insulation or new windows, a new HVAC system, siding, or remodeling your home. It just depends on what you’re having done and, in some cases, like HVAC, if the updated insulation will change your needs.
RetroFoam of Michigan has been working with homeowners to meet their foam insulation needs since 2002. With this experience, we know when it makes sense to install the foam first or wait until the other proposed work is completed.
Now, let’s take a look at some potential home improvement projects and whether insulation or the project should be done first.
Key Points: Home Improvements or Adding Foam Insulation
• The best order for foam insulation and home improvements depends on how much of the insulated area will be disturbed during the project.
• If a contractor needs to cut into walls, ceilings, crawl spaces, or attic areas after insulation is installed, it's usually better to complete that work first.
• Replacement windows can usually be done before or after insulation, but adding new windows should happen before injection foam insulation.
• Talk to an insulation contractor before replacing your HVAC system because better insulation can change the size and performance needs of your heating and cooling equipment.
• For siding projects, check with your siding contractor first -- some warranties may be voided if siding is removed after installation.
• If you need a full roof replacement, complete the roofing work before spray foam is applied to the roof deck.
• Drywall removal, major plumbing work, and electrical updates should typically happen before injection foam insulation to avoid damaging the foam or creating extra work later.
Foam Insulation or Home Improvement?
Deciding which project to do first really comes down to how much of the insulated area will be affected.
If you have to cut into walls that already have insulation installed, it could potentially be a problem. The same is true for crawl spaces or attics where the mechanicals are present.
Replacing Windows
The answer when it comes to windows varies depending on the scope of work that needs to be done.
If you are just getting replacement windows, then it doesn’t matter which work you have done first. It’s important to keep in mind that your window contractor needs to insulate the box around the window to prevent any future leaks.
It might also be a good idea to have the insulation discussion first, in case the drafts you’re feeling aren’t from the windows, but because you have little to no insulation in your home.
A game-changer in this scenario is if you are adding new windows. This means the contractor will be cutting into your exterior wall to create the window. You don’t want to have new windows created after having the foam installed.
HVAC System Updates
When it comes to your HVAC system, it is best to talk to an insulation contractor first before replacing it.
That’s because if you have little to no insulation in your home, then it’s not going to be comfortable or energy efficient. This is also going to have your furnace and air conditioner working overtime to try and maintain a constant temperature.
While insulation may not be the answer and your HVAC system may be on its last legs, you don’t want to try to fix something that isn’t broken and still have issues. The size of the HVAC system you need could change after your home is insulated with foam.
New Siding
This really depends on the contractor installing your new siding.
For more than 20 years, RetroFoam of Michigan has been installing injection foam insulation into existing walls from the outside. While we can remove the siding, inject the foam, and put the siding back on, making it look like it was never touched, some siding contractors say that removing the siding will void their warranty.
So, the question is, should you get the new siding first or the injection foam insulation?
This is a discussion to have with your siding contractor. If the removal of the siding will void your warranty, then it is best to do the injection foam installation first. If there is no stipulation, then you can pick and choose what meets your budget.
New Roof
Replacing the shingles and replacing the roof as a whole are two different things when it comes to insulating your attic.
Foam insulation sprayed on the roof deck is the best way to seal the envelope of your home. If you need shingles replaced on your roof after this has been done, then there’s no problem.
If you are in a situation where the entire roof needs to be replaced, then it is best to do the roof before the spray foam.
Removing Drywall
A big one we discuss a lot with homeowners is drywall.
There is no question that if you are planning a renovation involving the removal of drywall, you should wait to have the injection foam insulation installed. This is because if you remove the drywall after the foam has been installed, you run the risk of pulling that insulation out with it, and you can’t just push it back in – it just won’t work.
You can also have spray foam insulation installed in the wall cavity before the new drywall is put up.
Adding Electrical or Plumbing
Fishing electrical wire or pushing pipes through injection foam insulation isn’t difficult, but it depends on your contractor's experience.
Foam insulation is pliable enough to push wires or pipes through, but some contractors don’t have the experience working with it. Because of this, when it comes to plumbing and electrical work, it is probably best to have those projects done before the foam insulation.
Get Foam Insulation for Your Home
Now that you know which projects make sense and when, you might have more questions about air sealing your home.
If you want to learn more, check out the Learning Center on our website.
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How to Insulate a Wall Without Removing the Drywall
Frequently Asked Questions
Should I insulate my house before replacing windows?
If you’re only replacing existing windows, either project can usually be done first.
However, if you’re adding new windows and cutting into exterior walls, it’s best to complete that work before installing injection foam insulation.
Should insulation be done before replacing HVAC?
In many cases, yes.
Improving your home’s insulation first can reduce heating and cooling loss, which may change the size of the HVAC system you actually need. This can help prevent overspending on oversized equipment.
Is it better to install insulation before new siding?
It depends on your siding contractor’s warranty requirements.
If removing siding later could void the warranty, it’s better to install injection foam insulation first. If not, the order may come down to budget and scheduling.
Can you replace drywall after injection foam insulation is installed?
You can, but it’s not recommended.
Removing drywall after injection foam is installed can pull the insulation out of the wall cavity, and it cannot simply be pushed back into place. If a remodel involves drywall removal, wait until after construction is complete for insulation.
Should roofing be replaced before attic spray foam insulation?
If you are only replacing shingles, spray foam on the roof deck is usually not an issue.
But if the entire roof structure needs to be replaced, it’s best to complete the roofing project first and then install the spray foam.
Can electricians and plumbers work around foam insulation?
Yes, but it depends on the contractor’s experience.
Injection foam is pliable enough for wires and pipes to be worked through, but many contractors prefer to complete electrical and plumbing updates before insulation is installed.
What home improvements should happen before foam insulation?
Projects involving major wall access—like new windows, drywall removal, plumbing, electrical work, and full roof replacements—should usually happen before foam insulation to avoid damaging the installed material.
