Finishing the exterior foam and stucco

Our exterior work was wrapping up in autumn 2012 when cold winter temperatures arrived in November and delayed the application of exterior stucco to the lower level. The area under the front porch was tented for warmth and stucco applied. But most of it remained bare naked through winter and early spring. By June 2013, exposure to sun and weather had started to degrade the surface of the 10-inch-thick blanket of Neopor foam that wraps the foundation. It was finally warm enough to try again.

Exposure to sunlight and the elements melted the foam.We filled in the gaps with new foam.The above two images show our repair patches. Also, the partially completed stucco from last fall had cracked.We have used masonary caulk on these cracks. Later, the stucco will be painted for a more uniform and lighter grey.The stucco product that we used was Parge-All 825, specially formulated to apply over foam. When the company was contacted, they suggested that cold weather caused the cracks last fall. The product  instructions say don’t apply if the weather drops below 40 degrees. However, when we applied new stucco at the end of August, we still got cracking, even with temperate weather.

Researching online information, combined with on the job testing, solved the problem. First, we applied a thin scratch coat to set up the surface of the foam, letting it dry for several days. This layer always cracked. Then we applied a final top layer that sets up without cracking. With our exterior foam repaired and the stucco applied, the house was buttoned up for winter 2013.



Attaching Neopor insulation blocks to the foundation exterior

Neopor insulation blocks are fitted and screwed onto furring strips. After the attachment , gaps will be filled with expanding foam insulation. The application of these blocks will complete the envelope of insulation running under the slab and footing, then up the exterior of the poured concrete foundation. The foundation and slab are completely insulated from ground contact and thermal bridging.

Applying spray foam insulation

Closed cell spray foam insulation is applied to fill the gaps between the deck i-beams.A smaller foam application pre-fills gaps.The first pass with the sprayer fills the corners helping to make the insulation airtight.Spray foam expands to fill the gap between the overhanging deck soffit and the foundation. This helps create an airtight seal between the deck and the foundation.The spray foam curing in place after the first application. Two applications were made on different days to fill out the thickness of the cavity.LVL’s are glued, screwed and sealed in place to finish the deck perimeter.

Sealing the soffit under the deck

The deck extends over the edge of the foundation, overlapping the 10″ blocks of Neopor insulation that that will attach to the foundation wall below. The underside of the cantilever is sealed to make the shell of the house airtight.The underside of each beam is glued with OSI SF-450 adhesive. The bead runs along the perimeter of the connection point. The screws go through in the middle to avoid breaking the bead seal.   The two-by-four lumber under the soffit is an attachment point for the Neopor blocks of rigid foam insulation. The blocks will be notched out to fit. All gaps will be filled with spray foam insulation.

Pouring the slab

Rain has caused delay. The slab is poured at the first opportunity of clear weather.4” of concrete poured on 10″ of EPS foam.Dan Gregg brought in extra hands for the slab pour.Dan and Rich from Dan Gregg foundations.Clearing our in-floor electrical outlet.Slab finishing.Edge polishing.Dan Gregg spent the day polishing the floor. The finished slab with expansion joints cut in place.The rain returned at the end of the day.