Insulation is essential to keeping your home at an ideal temperature and protected from outside weather conditions. Cutting insulation may seem challenging and messy at first, but with the appropriate tools and safety precautions in place it becomes an accessible task anyone can tackle themselves.
Always wear protective gear when handling fiberglass insulation, including gloves, long-sleeves, dust mask and eye protection. Doing so could prevent skin irritation as well as potential eye injury caused by airborne glass particles entering through breathing passageways and entering through open wounds in your eye sockets.
Fiberglass
Fiberglass insulation is an economical choice for many homeowners. Its moisture and airflow resistance lowers energy costs while it can be installed anywhere from walls, floors and attics to be cut with either shears or utility knife for easier cutting.
Cutting fiberglass batts and rolls is easiest with a utility knife equipped with snap-off blades, as it has longer and sharper blades than regular scissors, enabling you to slice insulation into smaller pieces with greater ease. A kitchen knife equipped with serrated edges may also work, as they offer greater flexibility when cutting through thick material.
When installing fiberglass pipe insulation in your home, it’s essential not only to mark where the pipe union will fall but also cut a notch into the insulation so the nut fits snuggly into its slot – this prevents air leaking out through its joints. Also remember to wear protective clothing while working with fiberglass as loose fibers may become airborne and cause eye, nose, and lung irritation.
Batts
Batt insulation provides an economical way of insulating your home. Made of fiberglass material pre-cut into sheets and designed to fit between standard wall studs, flooring joists and ceiling rafters snugly, R value insulation comes in different thicknesses and widths with either paper or foil facings or unfaced for optimal insulation results.
Utility knives with long blades make short work of insulation cutting. A sheet of plywood on the floor protects it from marks while providing a firm surface on which to slide your knife across, helping protect its edge and avoid dulling caused by cutting on concrete surfaces.
Eye protection should always be worn when cutting insulation to protect from airborne fiberglass pieces that could escape during cutting operations. Gloves should also be worn and having a wet/dry shop vacuum handy is highly recommended in order to collect debris in the air that flies off during this process.
Rigid Foam
Rigid foam insulation is made of hardened plastic sheets that can easily be cut on site for use as insulation on walls, floors and ceilings. Installed on sheathing it prevents damage (such as mold and rot) caused by direct moisture contact to framing members while providing higher R-values than plywood or fiberglass batt insulation products.
There are three primary rigid foam types, EPS, XPS and polyisocyanurate (polyiso). Of the three materials, EPS is generally the least costly but has lower R-values compared with its more durable competitors (XPS/polyiso). On the other hand, their greater durability means lower permeance rates than EPS as well as an extended service life.
Before beginning to cut foam insulation, be sure to lay it out on a flat surface so you can make clean cuts. Most types have foil backing that you can mark with a marker pen for ease. In addition, you will require a tape measure, sharp utility knife and work gloves.
Mineral Wool
Mineral wool (also referred to as rock wool or slag wool) is one of the most commonly used insulation materials for residential homes. Crafted from natural rock and steel slag recycled from iron ore and steel production industries, mineral wool provides effective fire resistance without needing chemical-based flame retardants.
Mineral wool provides excellent thermal and acoustic insulation, thanks to its porous structure which keeps air moving within building’s framing cavities, helping reduce sound transmissions. Furthermore, mineral wool’s moisture-resistant qualities help inhibit mold, mildew and other harmful microorganism growth that would otherwise promote it’s use as insulation material.
Mineral wool insulation tends to be more costly than its fiberglass batt counterparts, although costs can differ depending on your region and eligibility of home energy efficiency programs. Furthermore, installing mineral wool requires more time and skill compared with other forms of cut insulation; batts must typically be cut down to fit around electrical boxes, plumbing pipes, wires and any other obstructions present during installation.