Posts Tagged ‘EPS’

Second Floor Done

After losing three more days to rain, we are back on track!  Intellistructures spent one day building the upper level floor system and one day putting the second floor together.  That leaves the roof panels to be set, which will hopefully happen on Monday.  By then, we will have the SIPs shell and be ready for roof dry-in and outsulation to be attached.  Similar to the foundation, two inches of EPS foam will be attached to the outer skin of the SIPs panel going from roof, walls down to where we left off on the foundation walls.  Stay tuned!

2nd Floor North View

2nd Floor South View

Interior View

12 Inch (R-46) Roof Panels


SIPs are here!

After delays of every possible kind which I can’t bear to relive by writing about them, we finally have our Structural Insulated Panels (SIPs).  SureTight delivered them this morning.  For the walls, they are 8.25 inches thick (7.375″ Neopor EPS), giving us an R-Value of 35.  For the Roof, we’ll have 12.25 inch (11.375″ Neopor EPS), giving us R-53.  These R-values are not exact due to some lumbers between the panels.

Intellistructures will begin putting up the panels on Monday.  We hope to have a dry-in shell by the end of the month.

Here are some pics.

8.25" Neopor SIPs

More SIPs


Don’t know how SIPs are made? SureTight shows you how

Another day of heavy rain!  What better thing to do than drive to Youngwood PA and learn how SIPs (Structural Insulated Panels) are made?  SureTight is a small SIPs manufacturer in PA.  They serve builders and homeowners all over the East Coast who want to build an airtight and very well-insulated home.  See their site here and be sure to take a look at their projects.

The oweners/partners Tim and Jim showed us how a SIPs Panel is built.

First, you start with foam.  What you see here is BASF’s Neopor EPS foam which has about 20-25% more R-value than the regular EPS (white).

Neopor EPS

EPS stands for Expanded Polystyrene.  It’s various uses range from coffee cups, insulation to packaging materials.  Watch the video below to see how it’s made.

So, because it is expanded, quality control is very important.  SureTight weighs every piece of foam to ensure it has enough density to be made into building material, then they check for an UL stamp.  Next, a carefully measured amount of glue is applied on a two pieces of OSB (Oriented Strand Boards).  This is not your Elmers or some organic horse glue.  This glue is formulated for structural use in building materials such as SIPs, I-joists and other laminated wood products and it is made to be highly resistant to moisture.

A giant tub of glue

The foam gets sandwiched between the OSB and the whole thing gets pressed through this machine.

SIPs Laminator

Then, the panel is placed in a top secret vacuum press to compress it while the glue sets.  Other companies use a hydraulic press for this.  Finally, you have a panel.

The panel then gets fed into this Hundegger CNC precision cutting machine to be cut to size.  When it comes out, the panel is extremely exact and cut with laser precision and that is because it uses lasers to ensure that level of accuracy and precision.

Window and door rough opening are then cut at a station.

Panel with Rough Opening


After all the excess foam is removed.  The panel is ready for shipment.  Some of these are ours!

Finished SIPs

SIPs can be made to all different shapes, thicknesses and sizes, it all depends on the needs of the builder/homeowners.

Different Shapes

Foam, lot of foam!

Last week, we successfully set the foundation walls. Two days later, Peed Plumbing came and completed the ground works in 100+ degree weather!  They did an excellent job despite the heat.

Ground Works

On the same day, Universal Foam made the first of their deliveries.  The driver and I unloaded the foam.  This is probably about half of what we will eventually put on the house.

We have three different specifications. 4″ EPS, 2″ EPS and 1″ XPS (The blue/green stuff).

Here is the idea.  We will insulate under the slab with the 4″ and 2″ to achieve a 6″ under-the-slab insulation.  This foam is treated to guard against termites.

With the 6″ slab insulation, we still don’t have a continuous insulation from the walls to the slab because there is no foam underneath the wall panels.  The 1″ XPS will be laid on top of the concrete slab all the way into the cavities of the Superiorwalls to connect with the wall insulation, thus forming a continuous insulation layer.

See this drawing for our insulation details:

Wall Junctions Slab to Ceiling-02

So, there you have it.

We know there are debates going on about insulation choices.  Here’ re our thought as related to this project:

1. Should we use foam at all?

Some people would prefer not to use foam at all because after all, it is still a product of the oil industry.

The alternatives are:

  • Cellulose (R-3.47/in): recycled newspaper, blue jeans
  • Stone wool (R-3.33): rock-based mineral fiber and recycled slag from steel and copper industries
  • Perlite (R-3.04): mined material, essentially expanded glass
  • Strawbale (R-1.45-2.18)

These all are great insulation choices but cellulose is probably a better material for indoors, we don’t want a house covered in newspaper (no one likes wet newspaper). Although, we may consider it as additionally insulation indoors.  Stone wool and perlite are both mined materials that might not necessarily be better for the environment than foam.  Additionally, we are not sure how we can keep it in place on the walls.  Strawbale is a great one too but perhaps when we actually build a strawbale home one day.

There are obviously others but there are few that matches the versatility of the rigid foam boards.  For our project, we need something rigid that can be used in outdoor and underground environments that can withstand moisture without physical deteriorations or drop in R-values.

2. What type of rigid foam?

We decided to use both, although mostly EPS.  XPS typically has a higher R-value than EPS (5.72 v.s. 4.17).  However, studies have shown that in long-term underground applications, XPS has the tendency absorb water and lose R-value.  EPS absorbs some water too but is able to maintain R-value.  This is why we decided to use EPS for all exterior and under-slab applications.  Above the concrete floor, we wanted a rigid foam board to break the thermal bridge along the entire slab edge and preferably one with a high R-value without the thickness to preserve basement floor height.  XPS seems to fit the bill.

From a sustainability perspective, XPS foam is worse for the environment because it uses hydrocarbon-based gas as blowing agents.

Anyone who is more knowledgeable about this, please feel free to comment.

%d bloggers like this: