healthy home Archives - Living Craft

Dearborn House Remodel

This deep energy retrofit started with gutting a 1960s house to add new wall and attic insulation and air sealing for maximized energy performance. We eliminated the natural gas line and transitioned to all electric heating and cooling and equipment and ERV, powered by rooftop solar panels. Other details include a new EPA certified fireplace insert, in-floor radiant heating, plastered walls and ceilings, a tadelakt shower, and integrated soapstone sink. We built a mudroom addition to connect the garage, laundry room, new back patio and expanded kitchen, and a detached outbuilding/barn for workouts and shop space. Design by Shelterbelt Architecture.

7 Reasons to Keep Your Old Plaster or Plaster New Walls

You could say that lime plaster forms the foundation of our company, or at least of our origin story. The three of us met on a big lime plaster job in the mountains west of Boulder, CO. We each contacted our mentor, Ryan Chivers, because we had heard of his reputation in the natural building community as a lime plaster expert. Frank had worked with him for a year at that time, and this project was mine and Ben’s first time meeting Ryan. He brought us on to help him sling plaster on both the exterior and interior of this strawbale mountain home. And, as they say, the rest is history.

Here are a few of the reasons we love lime. Whether it’s found in a historic home where plaster was the primary choice for wall building at the time (lime or gypsum), or a new build or remodel where the homeowner chooses to use plaster, this material is definitely not out of style.

1. Beauty

Have you heard the word birefringence? I hadn’t either, until I met Frank. Wikipedia defines it as so: “Birefringence is the optical property of a material having a refractive index that depends on the polarization and propagation direction of light.” Well, maybe that cleared things up for some of us…

The point is, because lime plaster cures back to it’s original material of limestone, it maintains some of the aesthetically enchanting qualities and depth of a natural gemstone or mineral, while being customizable in texture and color.

2. Durability

We all know that something that’s rock solid is very dependable. So, if someone gave you the choice to have walls that are literally rock solid, wouldn’t you take them up on that? It sounds like a no brainer to me.

3. Easy to Repair

One miraculous feature of lime plaster is that it is actually constantly repairing itself on a microscopic level. When small cracks form, new lime is exposed to air and moisture, which causes a continuing reaction which can self-heal smaller cracks. In case your lime plastered walls do get some bigger cracks, or a couple scratches, or an historic wall system needs repair, lime plaster can be repaired by a skilled plasterer. There are even artisans replicating plaster relief art in historic renovation.

4. It’s got History

Today, I told a material supplier that the products I was picking up were going to be used on a exterior plaster job, using lime plaster. He looked surprised and said, “Now that’s old school.” And he is not wrong! But the best thing about an old school material like lime it that it’s tried and true. And lime has been used in building mortars and plasters since the Greek and Roman heydays.

5. Low Carbon Footprint

As lime cures, it actually absorbs CO2 from the atmosphere. While there is still energy input during the production and shipping of lime (we call this it’s embodied energy), the curing process helps to offset this carbon footprint. Plus, lime is a more local product in many locations, particularly here in the Denver area, which means less fuel is burned for transportation than a cement stucco or paint.

6. Support your Local Craftsmen and Craftswomen

Many trade groups and magazines are extolling the virtues of skilled craftspeople in construction. The hashtag #keepcraftalive is one example I saw recently. Like many trades in the building industry, the workforce of skilled plasterers is diminishing. Hiring a local plaster company is one way to help rekindle the movement of skilled laborers coming up in the workforce. Plus, dollars spent on local products and with small businesses are more likely to stay in the community.

7. Improve Indoor Air Quality

Plaster improves indoor air quality in a few ways. One is that lime plaster contains no chemicals that can off-gas into the indoor atmosphere. Those are things like VOCs (found in some paints and stains). Instead, plaster is made of solely natural materials like sand and lime, with nothing that will emit noxious chemicals into the home.

Another way plasters improve air quality is managing humidity levels. We wrote a full blog on plaster and humidity over at our plaster specific website, Living Plasters. The general idea is that whether humidity is too low or too high, it can be bad for indoor air quality, or make your home feel uncomfortable. Plasters act as a buffer to moderate humidity levels in the “Goldilocks Zone” of just-right.

Personally, I’m excited to be part of reviving the lime plaster movement and beautifying our homes and buildings.

Case Study: A Straw-Cell Addition

Living Craft Design has been working on a straw bale addition to our friends’ home in Boulder. This family is already well-versed in the benefits of natural building, so their addition incorporates passive solar heating with large, south-facing windows and a concrete slab floor to hold all that sun-generated heat. The addition has the high insulation value (R-value) that is a great feature of straw bales as a building material. Additionally, the family chose to renovate the original rooms of their home and filled the walls and ceilings with densely-packed blown cellulose as part of that process. This home will be comfortable year-round and have low energy bills as well as a reduced need for running heating and cooling systems.

A Straw-Cell Design

We jumped into the project starting with straw bale installation. This house has what’s called a straw-cell wall, with an entire wall system behind the bales, complete with wood studs, recycled denim insulation, and exterior wood siding. The bales then are stacked on the inside of this wall, meaning that labor is reduced because you don’t have to cut or trim as many bales to fit within and around the walls’ wood frames. You also only need to apply plaster to the interior side of the bales.

Low Carbon

A great thing about the insulation materials used in this home is that they are all carbon-based, and will now be locked away in the walls of this home for a very long time. This is actually a form of carbon sequestration, one technique to keep atmospheric carbon down and help mitigate climate change. This is in direct contrast to insulation materials like foam, fiberglass, and mineral wool, which consume a lot of energy to create. This means that the manufacture of those materials produces a lot of greenhouse gas emissions, upping their carbon footprint.

Healthy, Natural Plasters

Applying a base layer of clay plaster at the work party.

Our next step was to start the plasters. A base coat of local red clay was applied to cover the bales first. At a fun summertime work party hosted by the family, we added a leveling coat which will provide the base and shape for the finish plasters. We introduced some folks to the techniques and tools for mixing and applying natural clay plasters and played in the mud with good friends. We also started to build out the windowsills into their final shape using a lime and clay mixture with lots of straw for strength.

Ben talks building with some volunteers while others work on shaping the windowsills.

The finish plaster drying around the laundry room window.

The final wall finish was customized to get the exact color and texture that our clients wanted, and this last, thin layer of clay-based plaster went on like a dream. Thanks to additions like wheat paste, it dries into a hard and durable finish that will last for years, and also be easily reparable in case of accidental damages.

During the wall finish process, we were preparing for and creating the tadelakt windowsills that will become perfect benches for sitting on and reading in the natural light. This Moroccan finish plaster is created from lime, which is why the base coat for the sills incorporated lime with the clay. This results in a tight bond between the materials. The smooth layers of lime were applied, soaped, and burnished using stones to create a shiny finish. The sills were then waxed as the final step to create a long-lasting surface that can withstand some use.

The burnished and waxed tadelakt windowsills have an amazing shine and reflection, as well as feeling silky smooth.

The End Result: A Beyond Green Building

We’re departing this project with lots of hope for the future which will unfold in this family’s happy, healthy, non-toxic, and environmentally friendly home. Not only will it be a beautiful space to raise a family, but also a good model for other front range homeowners looking to sustainably add some space and renew their original home.