Tuesday, January 1, 2013

Burlap Cement & Asphalt Emulsion Experiments

This so-called gazebo structure is an amalgam of papercrete recipes. In that way it taught me a good bit about papercrete -- the recipes improved over the weeks of layering. But some of the areas first covered are soft, and rain was actually eroding them. I wanted to extend the umbrella roof, creating an eave for aesthetics but also to help keep the rain off those soft sections until I can invest the time to save or re-do them.

The roof is made from a picnic table umbrella coated with a latex paint/cement/sand mixture. It seems to be holding up, but I didn’t see how to attach lathe or hardware cloth as an armature for an eave.

I wound up using raw burlap soaked in bonding agent, then saturated with crack resistant grout. I was inspired to try this approach by this great website (http://annesley.wordpress.com/burlap-crete-explained/). I could not find the rapid set grout this author writes about, and settled for Quickrete Professional Crack Resistant Grout purchased at Lowes.

Doing a section the width of the burlap  at a time, I just lay a double layer of the grout-saturated cloth in place at roof's edge and used a board to prop the overhang up until it cured. I wrapped the board in cellophane sandwich wrap to help keep the grout from adhering to it. After I saturated the burlap with grout and positioned it, I added more layers of grout, then let it cure several days before removing the board. I wouldn't try to do pull-ups from it, but it seems very sturdy.

I've begun layering the entire roof with a papercrete mixture including asphalt emulsion (2 parts sand, 2 parts cellulose, 1 part portland cement, a nice gob of asphalt emulsion. I let the dry mix tumble in the mixer for awhile, put a little in a bucket, added water, drill mixing until crumbly, then mixed in the asphalt emulsion by hand).

I'd used this mix layering a section of the gazebo (the issue at that time was getting papercrete to stick to the armature, and I really like the finished product. I'm interested to see how this mix holds up to the South Carolina humidity, sun, and heat. I'm trying to create a sort of layered, thatched look on the roof.


  1. Thanks for sharing with us this kind of information really great for us.

  2. I found this post of yours to be really helpful and guiding. Thanks for sharing your ideas with us.

  3. So far this roof has held up well. I just completed a similar roof on my outdoor shower project, covering an old umbrella with paint-crete, mortar, and finally with a papercrete/asphalt emulsion mix. I've also been using a touch of asphalt emulsion in my papercrete mix on some sculpture projects.

  4. Great article, Thanks For Sharing information. Bitumen emulsions are created when bitumen and water are mixed together with the aid of an emulsifier. Bitumen can only be used to create roading products when it is heated to around 160C.