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Insulation, Moisture, Air & Pest Barriers Category

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Alternative Building System – SIP (What the heck is that? Read On!)

Wednesday, June 23rd, 2010

An alternative building system to a conventional stick built home is called SIPs.  SIPs is an acronym for Structurally Insulated Panels.  SIPs are made up of rigid form core insulation, laminated between two (2) layers of wood sheathing called OSB (Oriented Strand Board).  SIPs replace several components of conventional building such as studs and joists, insulation, vapor barriers and air barriers.  SIPs are most commonly used to build exterior walls but are also used for floor and roof systems.

Some of the advantages of using SIPs in building your dream home are:

  • A home built using SIPs will have a tighter building envelope, creating walls with higher insulative value and fewer drafts. This results in a decrease in operating costs while maintaining a comfortable interior environment for you and your family. SIPs have earned the US Government’s Energy Star designation.

Studies done by Oak Ridge National Laboratory (ORNL) show that when whole wall R-Value is measured, SIPs outperform wood framed walls. By eliminating the loss of heating and cooling energy through space in the insulation, SIPs dramatically reduce the amount of energy used to heat and cool your home. The ORNL also determined a SIPs room to be 14 times more airtight than an equivalent room with 2X6 construction, sheathing, insulation and drywall.

  • A SIPs home uses up to 35% less raw lumber than a traditional stick built home and generates much lower amounts of construction site waste.
  • The indoor air quality for a SIPs home is superior to conventional construction because there is no release of chlorofluorocarbons.
  • There are no bulging studs, twisted lumber or shrinking wood due to drying with SIPs, therefore the walls are straighter making cabinets, tile etc., easier to install on flat walls.
  • Pictures, towels bars, medicine cabinets and lighting are also easier to install because you don’t have to find a stud, there is OSB behind the whole wall.
  • SIPs are naturally fire resistant because there is no oxygen in the form core.
  • SIPs are highly insect and mold resistant.
  • SIPS are highly wind resistant, having been tested at 200+ miles an hour winds with no damage. This is equivalent to more than a level 5 hurricane.
  • SIPs are earthquake resistant and have been tested at 7 on the Richter Scale with no damage.

In 1995 in Kobe Japan, there was a devastating earthquake.  One of the only buildings still standing with minimal damage was a SIPs building.

  • SIPs are very easy to install which saves time and labor costs. According to recent statistics, there is a savings of 30-35% in the time required for construction using SIPs methods compared to stick built methods. The exterior walls and roof can be constructed in eight to ten hours for a typical 1,600 square foot home.

While initially SIPS may be more expensive that conventional stick building, the savings in time to build and reduced ongoing energy costs can more than make up for it.    If you are working with a UBuildIt Construction Consultant, they can help you decide which might be the best option for your dream home design and budget.

Insulation, how does it work & what works best for me?

Tuesday, March 16th, 2010

Heating and cooling your home represents almost one half of the money you will spend on energy every year.  If your home is poorly insulated, those costs can be even greater. The amount of insulation as well as its effectiveness is “key” to your energy usage.

By nature, heat flows from a warmer area to a cooler area due to the difference in temperature. So in winter, the warm air in your heated rooms will move to the cooler unheated areas such as the attic, garage, crawl spaces or outside.  During summer, the warm outside air will transfer to the cooler interior of your home because of the higher temperature outside as well as the admission of sunlight.  In either case, your HVAC (Heating – Ventilation – Air Conditioning) system must work to replace or remove the heat lost or gained.  The effectiveness of your insulation will directly impact how hard your HVAC system must work which then directly impact your energy costs.

graph

Insulation’s role is to slow down the transfer of heat.  This is measured in its ability to resist air flow, which is called R-value (resist value). The higher the R-value is, the greater its resistance to heat.  Its R-value will be determined by the type of material it is made from, the thickness of the insulation and the density of the insulating material itself.

There isn’t just one correct R-value for all areas of the country or for all areas of the house.  Shown below is a table prepared by the U.S. Department of Energy for Targeted Insulation levels for different areas of the country and locations within your home. Take a minute to review this chart and see where you are.

Target Insulation Levels

Location

Southern Region

Northern Region

Good

Great!

Good

Great!

Ceiling/Attic

R30

R38

R38

R45

Walls

R13

R19

R19

R23

Floors

R9

R25

R25

R30

Basement Walls

any

any

R11

R19

Slab

any

any

R4 or R5

R8

If you want to know what the R-value of  the insulation in your current home, either look for an “energy label” containing the home’s R-values near the main electric service panel or near the hatch or stairway .  If you can’t find a posted energy label, look directly on the insulation for the R-value or measure the actual thickness of the insulation.

In addition to the R-Value, installing your insulation correctly is critical to its effectiveness.

There are five (5) common installation problems that can occur. problems

  1. One of the types of insulation is Batts. If it is compressed it will provide less resistance to heat and can provide a channel for air and heat movement.
  2. If your Batts or Vapor Barrier is stapled to the inside of the studs, unwanted air movement can occur between the studs and the insulation.  It should always be stapled on top of the studs, allowing the Batt to completely fill the cavity in which it is placed.
  3. Not completely filling irregular areas or small voids with insulation can cause heat loss.  A void of 1-2% can result in a 25-40% loss in R-value in that area.  It is for this reason; different types of insulation may be used in the same home.
  4. If you don’t install loose-fill cellulose insulation to its property density, heat loss can occur.  The proper density is called fluffing.
  5. Heat can be conducted through the studs and joists of your home.  This is called short circuiting or bridging the insulation.  With careful design and proper installation, this can be minimized.

While your contractor will be looking out for these common problems, it is helpful for you to know what will be affecting your energy costs for the life of your home.

Some areas of your home will have a greater opportunity for heat loss than others.  If you have to prioritize which to insulate first, this is the recommended order:

  1. Attic, including the attic door or cover hatch
  2. Beneath floors above unheated spaces such as garages, unfinished basements and crawlspaces
  3. Around walls in an heated basement or unventilated crawlspace
  4. Around the edges of a slab-on-grade foundation.

As you work with your architect or designer and contractor, ask questions about how your home will be insulated.  This planning can save you money in the future as well as protect the earth’s precious resources.

What are the different types on insulation in a home?

One inch of insulation = 30 inches of concrete

There are nine (9) types of insulation used in home construction and remodeling today.  The type of insulation used can be based on the area of the house needing insulation as well as the cost.

The R-Value of Fiberglass insulation is 3.14 per inch

1. Rolls and Batts – These are blankets of flexible products such as fiberglass or rock wool and come in continuous rolls with widths suitable for standard wall stud spacing and attic or floor joists. rolls and batts

These can be purchased with or without vapor retarder facings as well as a one with a special flame resistant side for basement walls where the insulation will be left exposed.  This type of insulation is great for areas which have standard stud and joist spacing and are relatively free of obstructions.  They do not readily fit irregular spaces and can create insulation voids. Loose Fill or Sprayed-in-Place insulation is more effective in these irregular locations.

A void of 1-2% can result in a 25-40% loss in R-value in that area


2. Loose Fill – This insulation is made of cellulose which is recycled, shredded newsprint and is chemically treated to resist fire, and fungal and insect growth.  These shreds are blown into space with special pneumatic equipment and are well-suited to irregular areas where other types of insulation are difficult to install well. loosefill

The R-Value of Cellulose Insulation is 3.70 per inch.

Cellulose must be installed at a density of 3.5 to 4.4 pounds per square inch to ensure it will not settle and that gaps do not form.  When having cellulose installed, always get a written guarantee of the settled depth from the installer.

Manufacturers use recycled waste materials in the production of loose fill insulation.  Cellulose contains more then 75% recycled newsprint


3. Sprayed-in-place – This insulation uses cellulose, fiberglass and mineral wool that are mixed with an adhesive and spray in insulatoinblown into wall cavities.  When properly installed, wet-spray insulation resists settling and shifting, and allow the cavity to be completely filled.

4. Foamed-in-place – This type of insulation is typically more expensive than the fiber insulation but is very effective where higher R-values are required or, in irregular areas of your home which would not be adequately covered by a Batt type insulation.  Foamed-in-place insulation is either polyurethane or isocyanurate and is applied by a foamed in placeprofessional using special equipment to meter, mix and spray the foam into place. Foam can be used for a variety of applications but is especially effective with irregular-shaped surfaces and narrow openings such as shim spaces around doors and windows.  The foam does not act as a vapor barrier and should be protected from prolonged exposure to sunlight.

5. Foam Board – Foam boards are rigid and lightweight, and provide structural support and acoustical insulation.  foam boardThese are designed to be used in confined spaces such as exterior walls, basements, exposed foundations, attics, concrete slabs and cathedral ceilings.

6. Radiant Barriers– These are manufactured from aluminum foils and are used to reduce cooling loads.  The common use is under roof rafters to reduce the heat gain from the sun or, on walls that absorb direct sunlight, I.E., walls facingradiant barrier west without an effective roof overhang.  Because they are designed to reflect the heat, they work well in warm climates but are not recommended in cold climates.

7. Reflective Insulation systems – Similar to the Radiant Barrier, the Reflective Insulation is made from aluminum foils reflectivewith a backing of kraft paper, plastic film, polyethylene bubbles, or cardboard.  It is typically used between roof rafters, floor joists, or wall studs because it is most effective in reducing the downward heat flow.

8. Insulating Concrete Forms (ICF) – These serve as both insulation and as part of the wall assembly of your home.  The forms are made of two foam insulation boards and are connected by plastic ties.  Concrete is poured into the forms and the forms are left in place for their insulative value. icf

ICFs can cost up to 4% more than the standard wood framing but a home built using this product requires an estimated 44% less energy to heat and 32% less energy to cool when compared to an equivalent wood-framed house. U.S. Dept. of Energy

9. Structural Insulating Panels – SIPs are made up of rigid form core insulation, laminated between two (2) layers of sipwood sheathing called OSB (Oriented Strand Board).  SIPs replace several components of conventional building such as studs, joists, insulation, vapor barrier and air barrier.  SIPs are most commonly used to build exterior walls but are also used for floor and roof systems.

Work with your contractor and architect, or designer, to carefully plan how the insulation in your home will maximize the effectiveness of your HVAC system and lower your ongoing energy needs. Your UBuildIt Construction Consultant can help you with these types of decisions.

What the Heck is ICF?

Friday, April 25th, 2008

With today’s modern technology there are many alternative products and techniques to build a home other than the traditional stick built home. One of the most popular alternatives is using Insulated Concrete Forms, also known as ICFs.ICFs are forms or molds with built-in insulation which accept reinforced concrete. (more…)

Tight Building Envelope? Why You Want One!

Tuesday, April 1st, 2008

A building envelope is a combination of the foundation, wall and roof assemblies all working together to provide a safe and comfortable environment for you and your family while maintaining the structural integrity of your home. In other words, it keeps your home tightly sealed to prevent the outdoors from coming in. The more tightly sealed your home, the less energy loss you will have. (more…)

How Does Insulation Work?

Wednesday, March 12th, 2008

Heating and cooling your home represents almost half of the money you will spend on energy every year. If your home is poorly insulated, those costs can be even greater. The amount of insulation as well as its effectiveness is key to your energy use.

By nature, heat flows from a warmer area to a cooler area due to the difference in temperature. So in winter, the warm air in your heated rooms will move to the cooler, unheated areas such as the attic, garage, crawl spaces, or outside. During summer, the warm outside air will transfer to the cooler interior of your home because of the higher temperature outside as well as the admission of sunlight. In either case, your HVAC system must work to replace or remove the heat lost or gained. The effectiveness of your insulation will directly impact how hard your HVAC system must work which then directly impact your energy costs. (more…)

Keeping the Heat & Cold Out of Your Home – Insulation!

Monday, January 28th, 2008

Today, there are nine (9) types of insulation used in home construction and remodeling. The type of insulation used can be based on the area of the house needing insulation as well as the budget requirement for that item. (more…)

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