Building a rustic backyard escape

by Sally Bouorm | April 1, 2014 10:54 am

[1]

By Markus Winkler and Karen J. Williams

Editor’s note: This is the second in a two-part Landscape Techniques feature on planning, designing, and building a natural swimming pool (NSP). The first article, ‘Designing A Rustic Backyard Escape’ appeared in Pool & Spa Marketing’s February issue.

After finalizing the plans and design with the clients for the Okanagan gold rush project, the next step was a massive cleanup and preparation of the land where this approximately 7.74 m² (12,000 sf) backyard feature would be created. The general plan outlined the gold rush cabin, outdoor kitchen structure, putting green, and the natural swimming pool (NSP)/pond. The land preparation had to be performed in an environmentally sensitive manner not only to be less invasive in general, but also to try and save as many of the existing plants, shrubs, and trees as possible to incorporate them into the final landscape plans.

In the heat of the moment

During the cleanup process, the weather became warmer and quite dry, which made it necessary to start excavating the land sooner rather than later. During the decision process of what plant life could be saved and re-used, a 36.5-m (120-ft) tree needed to be prepared for the construction phase and the eventual changes in the yard.

[2]

[3]

To do this, an arborist was hired to properly prepare the tree by trimming it and analyzing its root structure not only to protect the tree during the construction process, but also to prepare it for a long future after the NSP was constructed.

Before excavation commenced, it was documented that within a very short period of time, water started collecting, which eventually amounted to approximately 0.3 m (1 ft) sitting on the proposed area where the NSP was to be built, despite the fact the drier weather had come.

At this point, the crew had not yet broken ground so a test dig was performed to determine the structure of the underground area as well as the possible respective water flow. At this point it became clear that the crew would be forced to work with an extensive dewatering process to contain the water and direct it into the storm sewer to facilitate a proper excavation. The company hired to handle the dewatering process during this project were proven professionals in their field with references to the Kelowna H2O public swimming facility. For this project, the dewatering process took place 24-hours a day, which meant the team had to work on the filtration and the swim zone areas at the same time. This is not always the case on each project; therefore, 24 well points, located 4.8-m (16-ft) deep with a 6.1-m (20-ft) deep manhole was needed to take the pressure off the entire construction area. This drainage system was installed beneath the NSPs’ membrane.

Figuring out the filtration pond

Before executing the filtration field in the filtration pond, another test was performed with regards to the water quality to ensure the calculation of the final filtration depth remained accurate and was still within the quality range of the original design. These test results, which are done for each project, cost in the range of a few hundred dollars, depending upon the area, and are well worth the investment.

The results for this test took approximately a week to receive; this timeline again is dependent upon each area, so it is best to conduct this test as early as possible to avoid any construction delays. In cases where the water quality has changed, modifications can take place to avoid unnecessary challenges at a later date. The test for this project came back with the identical values as in previous tests, which allowed the project to be foreseen in a balanced environment.

Excavation: Trials and tribulations

[4]

[5]

After starting the actual excavation process, an underground creek bed was found to be the reason for the massive amount of water seeping through the ground; therefore, to prevent any future issues, the higher filtration pond was divided from the lower swim zone to stabilize the area. This was done using Type 1 concrete masonry units (CMUs) to avoid erosion and withstand any ground movement with the water flow. The design also included an underwater cave at the waterfall area; therefore, to support the giant rocks on top of the NSP membrane, a concrete slab was poured for stability.

[6]

After some well-organized work, within a few weeks the entire pond was excavated and ready for the thick, specialized NSP membrane to be installed, along with the protective felt for both the underside and topside of the liner. The membrane, which is sourced from Europe, arrives in 1.5-m (5-ft) wide and 23-m (75-ft) long rolls and was installed by a group of experts. Each job is unique in its design and, therefore, each liner is also created for this certain size and shape. That said, the liner is not an off-the-shelf product, but rather specifically cut and seamed for each NSP.

Skilfully installing the membrane

Within a few days, construction was ready to begin on the rock structure that was being built on top of the felt-protected membrane. Before this process can occur, however, special safety and performance quality rules are performed to ensure the liner is installed properly to eliminate the potential for any future problems from occurring.

[7]

For example, the installer on the heat gun seaming machine is not permitted to be the only person double-checking the seams; a different team member who was not involved in the seaming process checks the entire membrane for any spots that may have been missed as well as potential areas for leakage, product malfunction, or damage. Every team member is also specifically trained on how to work on top of the liner membrane to minimize any possible damage from occurring.

[8]

It seems logical for anyone working with a liner that certain precautions must be taken; however, if one has not worked on top of a membrane before, it involves some thinking outside the box as it can be a challenge. This is where job-specific training comes into place. For example, simple precautions such as making sure the bottoms of work boots do not have sharp rocks embedded in them is a simple, yet effective, way to eliminate possible punctures from taking place when a crew member is walking and/or working on top of the membrane.

Bring in the gravel and sand

After installing the protection felt, the distribution layer at the bottom of the filtration field was next on the list for installation. The design for this pond required three separate, and different, layers of a gravel and sand mixture.

Due to the property’s limited accessibility, a specialized excavator had to be used. This machine is capable of going where other excavators cannot; it can also be used on top of a membrane without causing any damage as it uses four ‘legs’ to walk into a construction site. This allows freedom of movement and agility, which was extremely important on this particular site. These legs provide several pressure points, thus spreading out the machine’s weight, while also evenly distributing the load it is carrying.

With the entire team’s hard work and determination, three layers of gravel and sand were installed within a week, and pockets for the filtration plants were created. The filtration pond was then filled slowly with water and ‘dry fitting’ started for the layout and location of the filtration plants.

Planting the seeds

The first priority was ensuring these plants were arranged properly so their roots were situated in the ideal water depth for the summer, when the pond is being used for swimming, and for the winter, when the pumps are stopped and the water level slightly decreases. The second priority was taking care during the planting process to ensure they were not only vitally functional, but also esthetically appealing.

Within 10 days, the filtration pond was complete and the plants’ roots started to settle down for future growth and development. It is of special note, in the first two years of a pond’s life, plant growth will be slower and somewhat minor, and in some cases, appear a little sparse than perhaps one would see in a mature pond; this is no different than in any landscape situation when a garden is new and freshly planted. In a filtration pond, usually by the third year, a big growth spurt can be seen, plant multiplication starts, and the foliage begins to fill-in. At this point, the maximum biological filtration capacity is typically achieved and the pond is in a situation of ideal balance.

The plant life, combined with the three layers of sand and gravel, act like a giant mechanical fine filter to purify the water, providing perfect water quality. The plant roots will provide bio filtration action and will begin to balance the phosphate (PO₄³⁻), nitrates (NO₃⁻), and sulfate (SO₄²⁻) in the water to perform their main function, aside from being visually pleasing. To create a biologically balanced filtration pond, local underwater plants were introduced as the best form of oxygenators. Plants such as large grasses and water lilies were also used to help keep the photosynthesis to a minimum, which in turn equals less algae and sediments for the filtration pond.

Creating a mountainside escape

[9]

According to the specific design of this project, the client’s desire was to have a mountainside lake-style swim pond. This required the need to bring in large-scale rocks, and a great deal of gravel and concrete to form a bed in which to set every single rock safely and permanently, not only to avoid damaging the liner from a sharp-edged rock during the construction process, but also for the safety of bathers. Therefore, it was important that no rocks would shift during the life of the product.

[10]

Given the magnitude and weight of the rocks, this required teams of at least two people to set them in place with the help of an excavator or crane operator. Often the rock work can be quite artistic, almost like piecing together a jigsaw puzzle or mosaic; however, not every NSP required the amount of effort and material as did this project. As previously mentioned, each design is unique to the needs and wants of the client for every type of budget in mind; the project presented herein was by far one of the most complex in terms of its design and construction[11].

[12]

While one team worked on the membrane, another team installed a 6.1-m (20-ft) shipping container onto the property, which would eventually be the outdoor kitchen and storage area. It also worked well in creating an attached pergola for the site of a barbecue and patio for a unique entertainment area. The sides of the container were covered by rock and vegetation; a green roof was also built to create a rustic and natural environment. The patio and path were built with flagstone to give the whole area a congruent look, integrating them with the pond to create a unique landscape.

The underwater cave

The underwater cave connected to the waterfall was one of the more challenging tasks in this project. On top of the poured concrete slab (mentioned earlier), extra-thick protection felt and 152-mm (6-in.) concrete padding was installed to build the base for 12 rocks, each ranging between 1800 and 9000 kg (4000 and 20,000 lbs). One particular granite-rock feature had dimensions of approximately 1.8 x 2.1 x 0.7 m (6 x 7 x 2.5 ft) and weighed in at a whopping 8845 kg (19500 lbs)—by far the heaviest rock in the pond.

After finishing the filtration pond and the swim zone with an underwater cave, time was spent on some of the project’s additional points of interest. These included two feature waterfalls between the filtration zone and the swim zone, and a creek behind a small island, which was created with an access bridge and a large entertainment deck. This deck has a lower swimming platform to serve as the main social gathering point and provides a stunning view of the waterfall and underwater cave.

Leisure areas

[13]

[14]

On the opposite side, a dock was constructed beside the sand bunker, which serves as yet another recreational area where the client can work on their short game, while overlooking the entire swim zone. The putting green and sand bunker is a great feature for any backyard party and the artificial turf can double as a place for sunbathing. Here, artificial turf is a great alternative to traditional grass because not only is it a low-maintenance feature for the homeowner, but there is also no risk to having grass clippings fly into the pond. Grass clippings would create an additional source of nutrients for algae growth.

What is a gold rush cabin without a mining cart?

[15]

Another backyard feature complementing the project’s overall theme was the installation of an authentic mining cart, complete with an engine on train tracks, which really sets the tone for this rustic gold rush project. Strategically positioned between the road and the barbecue patio, it also serves as a great sound and visual barrier to life outside the property, thus providing the homeowner complete privacy.

Also installed was a 5443-kg (12000-lbs) bubble rock in the centre of the filtration pond to not only provide water movement, which is vital to keeping algae at bay, but also to provide a pleasing audible sound to those enjoying outdoor life next to the pond. Nothing is more relaxing than enjoying the sun, sipping a fresh cool beverage and taking in the sound of babbling water lapping nearby. The final touches included finishing the edges of the pond with various-sized rocks and river rock gravel to harmoniously mimic Mother Nature’s designs.

The cutting pond edge

For NSPs it is extremely important to avoid surface water from seeping into the pond due to the external uncontrolled addition of nutrients to the existing closed system. To reach this goal, a closed-drainage system was installed around the entire pond edge. The specially designed pond edge is able to carry a 102-mm (4-in.) drainage pipe to prevent any unwanted water from trickling into the closed system, which is completely disguised with washed river rock gravel. This further lends itself to an unsullied finish combined with the assurance that surface water will not drain into the pond.

All of the aforementioned components and features would not be complete without the use of some technology to keep it all running smoothly. For this reason, a pump compartment was included to house this technology in an area hidden by trees to make it look less invasive, while maintaining the mountain-lake atmosphere. This waterway is powered by two eco-boost external pumps; a three-quarter hp for filtration and a two-hp for skimming and powering the water features (e.g. the bubble rock and creek bed).

A bio filter equipped with ultraviolet (UV)-lamps to treat the water is an efficient ecological method to avoid algae growth and first-grade infection risks. These systems have been tested and proven in residential and commercial applications for many years in Europe, a market which is regulated and governed by some of the strongest laws with regards to water quality and health.

One last-minute design change

[16]

As an aside to this project (and a true story), the owner’s Golden Retriever, Harley, watched the entire installation process. The whole crew could tell he was intrigued by the goings on as he loved water and looked longingly at the crew daily. Everyone knew what Harley wanted; therefore, before the construction of the bridge took place, boards were installed over the creek area so he could walk to the island, onto the wooden patio, to start enjoying the pond long before the finishing touches were complete.

A couple of weeks later, while the team was building the dock at the sand bunker location, the crew saw again how forlorn Harley seemed, just watching and waiting ever so patiently. The team leader called him on and Harley jumped at the invitation and immediately sprung into the pond, swam a lap and then began to look for a spot to get out, shake off and enjoy the sunshine.

At this point, it was determined a slight design change was required as Harley needed an easy way to get out of the pond once he had finished his lap, thus the ‘Harley Path’ was born. This allowed Harley to swim his round and exit safely via a gravel path by the second waterfall.

From that moment and on a daily basis, Harley would jump in, swim his lap and exit using his own personal path to play and lounge the afternoon away on the artificial turf.

 

Markus Winkler is the master designer and lead strategist for PoolsByNature, a designer/builder of natural swimming pools (NSPs) in Kelowna, B.C. He has more than 12 years of experience in the field of NSPs. Winkler has an engineering background in electronics and has received extensive education with respect to environmental and aquatic applications. He can be reached via e-mail at poolbynature@gmail.com[17].

 

 

Karen J. Williams is the design analyst for PoolsByNature. She has more than 20 years of experience in environmentally sustainable product strategies and is a member of the design team responsible for the connection between licensee partnerships and end-users while working with the company’s master designer.

Source URL: https://www.poolspamarketing.com/trade/building-a-rustic-backyard-escape/

---