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Landscape & Design

By Sophie Rhéaume • juillet 10, 2017

Concrete Porch Overlay Installation

Techo-Bloc

Paver Pete demonstrates how to assess existing conditions and the steps to follow for a concrete porch overlay installation. 

Picture1.pngConditions Assessment

 Rules:

  • Minimum pitch of ¼ in. per foot
  • No imperfection in the surface of the concrete greater than +/- 3/8 in. in 10 feet for drainage without pooling

Options for the coping:

We used the Bullnose Grande to compliment the pool coping on this project. All options need to be elevated with adhesive to allow subsurface water to get out. Ensuring proper drainage prevents moss, weeds and efflorescence.

adhesive elevate.jpg

Options for the field:

field options.jpg

Weeps in the masonry veneer:

  • Clean the weeps (holes) at the bottom of the wall and protect them with tape to allow the air to circulate and prevent condensation.
  • Allow a gap of about ½ to ¾ in. between the house and the overlay to let water escape and air circulate.

weeps.jpg

tape-1.jpg

Steps to follow

 

STEP 1: Install a foam cord, taped temporarily, along the wall to maintain a gap for water and air circulation.

foam cord.jpg

STEP 2: Install coping  with adhesive (see below for options) and use spacers to elevate it to have enough height to allow water to escape.

adhesive.jpg

STEP 3: Install geotextile (we used Gator Fabric) over the porch and up the sides of the coping to prevent migration of bedding material.

geotextile install.jpg

STEP 4: Install the bedding material (see below for options).

mason sand 2.jpg

STEP 5: Lay slabs on top of the pre-compacted bedding layer. The slabs should rest about 1/8 in. higher than the coping so water sheets off into the environment.

lay the slabs.jpg

STEP 6: Apply the joint sand (we used Flexlock Ultra, the industry’s only overlay-specific sand).

STEP 7: Consolidate the joints by tapping them with a rubber mallet.

mallet 2.jpg

STEP 8: Activate the polymeric sand following the manufacturer’s instructions.

Adhesive options: 

  • Flexlock: Polyurethane-based, expands into the pores of the concrete
  • Mortar with masonry cord: Install below the coping

 Bedding material options:

  • Washed concrete sand, #8, #9 & #89 aggregate. Be careful when the door sills cause a height restriction as the bedding layer's thickness is influenced by the particle size. 
  • OUR SOLUTION for when height is restricted: Brooming of C144 mason sand (less than ¼ in.).

Final result :

01052_09__25.jpg

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