DIY Insulation Do’s and Don’ts, Tips to Warm Your Home

A few DIY tips on insulation materials and things you should and should not do when insulating your home.

There are several types of home insulation and different applications for each. I will cover the different types and uses for each and offer a few tips to help keep your house warmer in the winter and cooler in the summer.

The most popular and widely used type of insulation is fiberglass -- which is actually made from spun glass. Fiberglass insulation is typically used to insulate floors, walls, ceilings and attics. It comes faced (paper backed) and un-faced, in various widths and R-values.

R-value is simply the measure of thermal resistance (how much the insulation slows the transfer of warm air to cold air). So the higher the R-value the more resistance the insulation offers. Learn more about R-value.

There are many other types of insulation such as;

  • Rigid foam (extruded polystyrene), used primarily for exterior applications.
  • Cellulose (made from recycled paper), used for insulating walls, ceilings, attics and floors.
  • Radiant barriers (closed cell foam faced on both sides with foil) use for insulating floors, walls, ceilings, attics, garage doors, water heaters and metal commercial buildings, and
  • Spray foam (a two-part liquid containing a polymer and a foaming agent) used for insulating walls, ceilings and other interior closed spaces.

These products all have different R-values, material cost and installation cost.

Do it Yourself Insulating Do's and Don'ts.

  • Do not crush or stuff fiberglass insulation into a space. Crushing the insulation reduces the effectiveness of the product. More in a space is not better.
  • Do wear a mask and protective clothing when working with fiberglass insulation. Who wants to breath spun glass into their lungs.
  • Do not block soffit and gable vents when initially insulating or adding insulation to your attic. Good air flow is critical to preventing condensation. Condensation/moisture will ruin most insulation and create an environment for mold to take hold.
  • Do install a moisture barrier (plastic/polyethylene) over your insulated walls and seal (tape) all seams as well as the top and bottom of the walls. This will help insure that there is less transfer of warm air to the cold air, thus virtually eliminating condensation.
  • Do not dispose of any insulation by burning. Burning insulation is toxic, harmful to you and the environment. You can easily dispose of the extra or old insulation by placing it in plastic bags and taking it to your local refuse disposal station (dump).
  • Do use radiant barriers to insulate the inside of your garage door and around your water heater. This is a great way to save energy and it is quite inexpensive. Radiant barriers are less expensive than rigid insulation, are far more effective and easier to use. Radiant barriers are also fantastic for use as a moisture barrier/underlayment for laminate floors over concrete. Since the radiant barrier acts as a thermal break the cold and moisture can not move from the concrete up through the flooring. It also adds just a bit of cushion to the floor for comfort, (as it is only 1/4" thick).

Follow these do-it-yourself insulation tips and you will truly succeed with speed.

If you have questions about your DIY projects, just ask your personal DIY consultant. I'm here to help you.

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  1. Thanks for the tips. Will definitely come in handy with cold weather coming in. I’m specifically interested in installing a radiant barrier.

  2. Is there a problem with spray foaming the underside of your crawlspace? Like if leaks happen or moisture getting trapped, or termites living above the foam. What is your thoughts on how the spray foam would work on a residential level?

    • Navedave,
      Spray foam is a very effective insulator but I would not recommend using it in areas where you would be covering up plumbing. Once applied the foam is difficult and time consuming to remove.

      I would recommend treating the crawl space for termites prior to insulating. Then to reduce moisture problems install a good quality vapor barrier on the ground.

      I recommend using a radiant barrier installed on the underside of the floor covered by faced fiberglass insulation. This will give you an excellent R-value and easy access to any plumbing etc. in the future.

      Quick DIY Tip; After installing the fiberglass insulation, use a permanent marker to make notes (on the fiberglass facing) of any plumbing or other utilities that are in the specific bays.

      Thanks for your questions.
      I’m here to help you.

  3. I want to install lamnant flooring over concrete and im concerned about cold transfering to the lamnant we have carpeting now and its warm but we really want lamnant can we install rigid insulation between the two?

    • Thanks for the question Judy, and for dropping by.

      I had the same situation in my home not to long ago and found that
      using a radiant barrier between the concrete slab and the laminate
      flooring works best.

      This Prodex radiant barrier is only 1/4″ inch thick and acts as a moisture barrier,
      thermal break, and a bit of cushion when walking on the floor.
      It installs with just a utility knife and some foil tape. No adhesives required, as it
      floats on the floor just like the flooring.

      You can purchase the Prodex radiant barrier at
      Be sure to buy Prodex as it has a closed cell foam center rather
      than the bubble wrap type.

      Also, be sure to tape the seams with foil tape (buy at your local home center).
      Remember, DO NOT overlap the seams, just butt them together so you have a
      nice smooth surface to install the flooring over.
      Once you have the product in hand, how-to butt the seams will make perfect sense.

      Also be sure to clean the floor well, prior to installation.

      I hope this answers your question.
      Thanks again.
      Your DIY Answer Guy

      PS; Please, let me know if you have any further questions,
      and how things come out, as I love to hear about your successes.

  4. We just tore out a bathtub and drywall. Is it OK to install paper faced insulation next to the hot water pipes of the shower? Thanks.

    • Yes it is OK to install the insulation next to the water pipes. If fact some people install foam insulation on their hot water pipes prior to insulating with fiberglass. Good luck on your project and let me know if you need anything else. Take care.

  5. How do you insulate a lightswitch when you feel cold air coming out of it

  6. Thinking of using Prodex for my basement concrete floor.

    How critical is it to install a plywood sub-floor on top of the Prodex prior to installing laminate wood floors?


    • I installed the Prodex directly on the concrete floor and then installed the laminate flooring directly over it with no issues.
      It’s been down for three years now. I’d advise filling any cracks or large dips with a concrete patch first.
      Let me know how things go.

  7. Hey Lary, I am insulating my basement with R-15 with paper backing… I was wondering when I install the insulation in the ceilings where the boiler pipes are, will the paper catch fire if it is laying on the pipe?

    • Kevin,
      Im not sure which pipes you’re referring to, the pipes that carry the hot water or the vent stack pipe for the fire chamber.
      Please let me know and send a picture if you could.

  8. We put fiberglass insulation in our crawl space (shares a wall with a bedroom) and then covered it with plastic to protect it from the elements (water, animals), but we were then told that the insulation needs more ventilation. Do we need to remove the plastic or perhaps cut slits in it to ventilate? Thanks for your help!

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