French Drains on Rolling Hills

Midtown Terrace San Francisco
By On October 29, 2015 In Completed Projects With No Comments Permanent Link to French Drains on Rolling HillsPermalink

Midtown Terrace San Francisco

The summer of 2015 found the Tamate Landscaping crew in the Midtown Terrace neighborhood. Like much of San Francisco, Midtown Terrace is built on rolling hills. –And while rolling hills make for beautiful landscape, they also make it hard for homeowners.

Falling retaining walls and sliding ground is often the culprit, but this time it was lack of drainage. The client had big concerns about water intruding into the home, thanks to the predicted El Niño.

The hillside butts right up against her house, and showed no evidence of a drainage system being installed during the home’s construction. Water marks were already noticeable in the garage foundation; if left unchecked water could start to cause dry rot. Dry rot, in turn, would continue to weep up the walls and cause very expensive damage.

We recommended a French drain, tied into the municipal drain system. With French drains, a trench is dug, and then filled with something (loose gravel, for instance) that helps vent the water before it seeps into the home. By tying it into the drain system, we would reduce the possibility of it seeping in elsewhere – basically wicking the water away from the home entirely.

Trench Around Property

The real challenge of this three-day project was excavating the rocky land. We needed to dig a 4’ foot (or deeper) ditch, which is a lot of work. The ditch had to be below the concrete slab of the basement. Otherwise, water could still gather at the base of the slab and weep into it due to concrete being porous.

Because of how rocky and compacted the soil was, we had to use jack hammers. We trenched down 5’ at the deepest level, to get below the concrete slab, and then discarded the removed soil.

Prepare the concrete

Once the excavation work is done, the next order of business is to prepare the concrete for the drain (Top image). As mentioned before, concrete is inherently porous and excessive water will penetrate, eventually seeping out the other side. A seal is added to prevent that from happening (Bottom Image).

Seal the concrete

However, before we could seal the exterior of the concrete, we had to make sure the concrete was clean. We used a high power washer to clean the concrete from any foreign material that would keep the sealant from bonding.

The sealant we used is a product called TamoSeal. We’ve been using it for 30 years, and we love it. TamoSeal is a Portland-based product that we often use in our pond construction jobs. It seals up all the pores, making the concreate water tight. It’s the extra protection this project needed.

Once the sealant was dry, we used a snap cutter to cut the old cast iron pipe leading to the municipal system. Since seeping water can carry dirt and debris into the drain pain, causing it to clog, the 3” perforated drain pipe we installed was wrapped in a fabric sleeve to help keep it clean. The last thing we want is to have to dig the trench back out because of a clogged pipe. We connected it to the municipal drain and then began the fill process.

The final step is to backfill the entire trench with tons of ¾” drain rock. Water follows the path of least resistance, and drain rock makes it easier for the water to get into the perforated pipe.

Drain Connect

Tamoa Seal

As an added layer of protection, we placed another black fabric barrier between the earth and the drain rock. This will ensure that the adjacent earth doesn’t slowly migrate into the French drain, which would eventually reduce its effectiveness.

All in all, it was a quick job; the hardest part was the digging. Even in our world of mechanical wonders, sometimes the best tool is manual labor!



Retaining Walls | Whitney Street – Glenn Park

Whitney Street Project

Glen Park Neighborhood

Glen Park, a wonderful neighborhood in San Francisco, could provide an entire semester of architectural material if you took the time to walk up and down the hilly streets. Spanish Colonial houses sit side-by-side with Mediterranean Revival homes, which butt up against homes built in Mission Revival style. It’s an interesting place with an interesting history, which was one of the reasons we were happy to take on a landscaping, garage stuccoing and retaining wall project on Whitney Street.

When we were called out for this project at the beginning of 2015, we were told that the client wanted a drastic change in improving curb appeal. We knew we had to keep the charm of the landscape consistent with the charm of the home. For a house on Whitney Street, full of 85-year-old (and older) homes, this is no small accomplishment. Although the home is modest, the front really makes it stand out from the dwellings on the street.

Another challenge was stuccoing the equally old garage and adjoining retaining wall in a way that would keep the stucco looking fresh and in one piece a few years down the road. Thanks to four years of little rain in the Bay area combined with San Francisco hillsides, stucco has a tendency to crack, and retaining walls can shift. Obviously, we don’t want either of those to happen.

We started as almost every landscaping project starts – with a little demolition, watched over by my work dog, Dukey:

Dukey Dog

Once all the old was out of the way, we could start the real work of beautifying the front of the home. Although a retaining wall was part of it, we also replaced the stairs and patio, add added a deck to the garage. We poured a new slab for the patio garden, built new stairs for the front porch and for the new deck over the garage.

Pouring New Slab

Bison Decking System

For the deck over the garage, we used the Bison Deck System, which ensures a smooth, even foundation for the wood tiles. This also provides a level step, rather than dipping and swaying when people walk on it.

We also installed new steps of black limestone and black slate. At night, the steps are lit by wall lights with a solid brass face plate. As always, we used FX Luminaire 12-volt lighting fixtures to illuminate the garden/front. FX Luminaire has always provided excellent products for landscape lighting.

Steps and Wall

Limestone Steps

To ensure the stucco on the retaining wall and garage doesn’t crack under the dry heat, we fortified it with metal lathe. Next is the process of applying the stucco, starting with a scratch coat.


As a final touch, we added custom iron fencing to the retaining wall, deck and stairs. This not only helped keep the style of the home, but also to set it apart from its neighbors.

Gate in Iron

Iron Work Steps

The Finished Project

We were really pleased with the final results. Within three weeks, we’d designed, installed and finished a flattering front entrance for the client. Tamate Landscaping did all the carpentry, electrical and stucco, which kept the price lower than if we’d had to go to outside contractors.

As well, we used an ironworker with long ties to the company to provide custom iron fabrication and installation.
Whitney Street Project

It was quite a job, but I think it’s one for the “well done” books.


Current Project 2014: West Portal Custom Front & Rear

By On January 18, 2014 In Completed Projects, Ponds and Waterfeatures, Retainingwall With Comments Off on Current Project 2014: West Portal Custom Front & Rear Permanent Link to Current Project 2014:  West Portal Custom Front & RearPermalink

Our first project in 2014 brings us back to West Portal and its a large one for San Francisco Standards.  Below is a shot of the rear before construction. We’ll be constructing new fences and sunken patios with contemporary concrete retaining walls that are becoming so popular these days.  Also included is a gas fire pit, stainless weir waterfearure, decks, lights and much more.


The end of 7 days.  After removing about 40 cubic yards of debris, concrete and dirt, you can see the forms for the new wall going up.



January 24, 2014, the end of week 2, we pumped 12 yards of  colored concrete (silver smoke), removed the forms on the same day and hand troweled for a smooth finish.



Also being installed is the rear wall stonework and water feature.


January 31, 2014:  Day 18.  

Things are moving along as planned and we should be done in about 7 days.  Below you see a test fire of the natural gas fire pit.  We installed a 30″  H- burner but now I’m thinking I was over ambitious.  The unit puts out so much heat that I’m concerned it may create superficial fissures in the concrete where its narrow.  Although the fire pit is a big chunk of steel re-enforced concrete, expansion and contraction of such material may cause an unsightly effect.  After a discussion with my clients, we are downgrading to a 24″ T-burner.  Stay tuned for a night shot.


A photo of Manuel in the background working on the “stainless weir” water feature.  Also, Mario in the foreground, ripping a piece of black limestone for installation.   A word about these two dedicated workers:  From the pueblo of San Mateo, Mexico,  they’ve been with me for 12 plus years and are the single greatest asset to my operation.   They are skilled, dedicated and with an unmatched dynamite work ethic.  Without them,  I simply would not be able to do an installation like this.


A photo of stair stringers made from 4″ pressure treated material.  All cuts have been sealed with “copper green”.   I’d say its elephant proof.


February 7, 2014:  2 shots of “Almost Done”








leni com 4

leni comp 1

Completed: West Portal Renovation Aug.2013

By On August 12, 2013 In Completed Projects, Retainingwall With Comments Off on Completed: West Portal Renovation Aug.2013 Permanent Link to Completed: West Portal Renovation Aug.2013Permalink

Below is a before shot of an uninviting, underutilized backyard.

chung before

We started with demo of the entire yard and concrete forms for a raised concrete planter which has become popular for todays contemporary styling.

chung planter forms

Planter number one with concrete forms removed.

Concrete planter number two.  This shot was taken 3 hours after the concrete pour.  Timing is crucial here.  Remove the forms too early and the whole structure will collapse.  Too late and it will be too hard to hand trowel a smooth finish.

kev 2

Winter 2013, Project Complete

chris comple 1

christ completet3

christ complete 2

Completed Project: Saint Francis Woods Curb Appeal. 7/2013

By On July 27, 2013 In Completed Projects With Comments Off on Completed Project: Saint Francis Woods Curb Appeal. 7/2013 Permanent Link to Completed Project:  Saint Francis Woods Curb Appeal. 7/2013Permalink

Below is a before shot of the front yard.  Client expressed a larger entrance patio that is more inviting and a general redesign to increase curb appeal.

The following three shots were provided by the homeowner and posted on yelp:  Below is a shot of the expanded patio.  Materials used were silver quartzite flagstone with a limestone border.  Note the FX Luminaire Brass step light.



Shot at night illuminated with FX Luminaire Copper LustroRame.


Completed Project: Outer Sunset Makeover, 6/2013

By On June 23, 2013 In Completed Projects, Retainingwall, SF Dept. of Building Inspection Permits/decks & retaining walls With Comments Off on Completed Project: Outer Sunset Makeover, 6/2013 Permanent Link to Completed Project: Outer Sunset Makeover, 6/2013Permalink

This residence in the outer sunset currently has crumbling concrete retaining walls/steps, terraces that slope and no foliage excepts for weeds.  Not a very inviting environment for a young couple with a new baby.  We were asked to provide a makeover, with a set strict budget and to include a deck, new steps, fix up the walls, turf and plants.  We were shown some photos of elements they liked and we took it from there.  Below are two photos of before.

We started with demo, relocating steps and reinforcing the existing walls.

Below is a shot of a massive concrete bench that we formed and poured.  It serves as as a safety barrier between the two terraces, a platform in which to tie the deck that we will be installing and also seating.

sunset forms

sunset deck

Adding new concrete to existing concrete must be done with great care.  The natural tendency is for new concrete to pull away from old concrete due to poor bonding and expansion and contraction of concrete.  We minimize this by anchoring rebar to existing concrete with a epoxy resin as seen below.

We also coat all surfaces of existing  concrete  with a bonding agent called Weld Crete as seen below.

Job complete.  Three new level terraces, new steps, an organic vegetable garden box, TREX deck and artificial turf.  Also installed were auto irrigation, lighting and plants.

Complete Projects: Retaining Wall in Buena Vista

February 13, 2013:

This project brings us to the Buena Vista neighborhood in San Francisco.  We’ll be replacing this wall with something much stronger.   A concrete wall is of course the most durable lasting 80 plus years but if budget is a factor, pressure treated (PT) timber is the way to go. But not all PT walls are constructed equally as you can see.  With the support post being the weakest link, failure occurs here in most instances.  Specifically, either the post rots out or the concrete footing will start destabilizing due insufficient depth and girth.


Tamate Landscaping - Old Retaining Wall

Day 1, old wall is removed and area excavated.

Tamate Landscaping - Old Retaining Wall Removal

So how do you make a standard pressure treated 15 plus year wall into a 30 plus year wall?  More concrete and substitute pressure treated posts with steel I-beams.  Here you see the steel post dropped into a hole 4′ deep by 2′ wide.  1/2 cubic yard of concrete will secure the post for a very long time.

Tamate Landscaping - Steel Support Beams for Retaining wall

Tamate Landscaping - Steel Support Beams for Retaining wall

Tamate Landscaping - Steel Support Beams for Retaining wall

As we excavate the post holes, soil is loaded onto the trailer for dumping and concrete mix brought up.

Tamate Landscaping - Soil and Concrete Loading

All with five gallon buckets.  A typical San Francisco project due to limited access.

Tamate Landscaping - Soil and Concrete Loading by Bucket

End of Day 3.

Tamate Landscaping - Support Structure for Retaining Wall

One very important process when working with pressure treated lumber is to seal all ends that have been cut.  When pressure treated material is manufactured, the chemical that protects it from rot, termites etc. is only injected about 20 percent into the surface ,at best.  Any cuts would leave that area open to intrusion of the elements.  Here we use “copper green” to seal it up.

Mira Drain.

Project Complete: February 2013, Buena Vista, San Francisco California.

Completed Project: Noe Valley Makeover 2013

Below is a photo of a rear yard in Noe Valley.  We installed the lower deck and fences about 6 months ago and soon we’ll be going back to finish the landscaping.  Included in the project will be a patio, stone planters, water feature, spiral stairs, curved bench/pergola, lighting, plants etc.

Here you see the completed quartzite patio and masonry work.  We used a bitterroot wall rock for the short retaining wall and a natural stone veneer on the existing concrete wall to cover the unsightliness.

View from the deck.  Note the curved redwood pergola which follows the contour of the patio.


We also installed a spiral staircase to provide access from the upper deck to the yard.  Spiral staircases are wonderful for small spaces as is typical in San Francisco.  They take up such a small footprint.  Tamate landscape acquires their made to order custom units from Salterspiralstairs and constructs them onsite.  This unit is aluminum and powdercoated.

We installed this simple water feature .  The cascade was made by cutting a channel into basalt.  The system re-circulates via a highly efficient pump which uses very little electricity.

Project shot at night with landscape lighting.

Current Project: Extended Project in Saint Francis Woods

By On October 29, 2012 In Completed Projects With Comments Off on Current Project: Extended Project in Saint Francis Woods Permanent Link to Current Project: Extended Project in Saint Francis WoodsPermalink

Project Complete:  March 22, 2013.

What began as a 2 month project on November 1, 2012 ballooned into 4 1/2 months due to never-ending delays caused by the general contractor.  It was an effort of persistence from all parties involved to get it done.  The following is some shots of our labor of love.


Project Update: Day 26 December 8, 2012

Finally work on paving begins.

Proper prep work and compaction is key to a stable surface.

With all concrete walls erected, grading and paving can begin.

Concrete forms for hot tub installation

Project Update: Day 16 November 23, 2012

Since the last update, we’ve been working on the forms for the second and final pour, which includes more curved retaining walls, steps, landings, hot tub walls and the pads for the storage shed plus hot tub equipment. We are a bit behind schedule due to delays and the rain. Below is Rocky-he figured out that this tent area is the place to be to stay dry.

Forms for main rear wall.

Future hot tub location.

This form for the rear landing will accept a single piece of 700 pound Connecticut Bluestone.

Project update: Day 11

First stage concrete complete. Planned 10 yards ballooned to 14 cubic yards. Below, a curved wall. Note the square tubes in the concrete that will accept future iron fence. Next, forms for second stage retaining wall plus paver installation.

1500 sq. ft. soccer field being prepped for installation with drainage running the the center.

Project Update: November 9, 2012, the end of day 8

It seems the rain is here making the past week a bit challenging. But we did manage to construct the concrete forms for the left and front walls as seen below. Next week we’ll be pumping our first 10 yard batch of concrete.

Project Update: Demo complete

After 40 cubic yards of concrete, greenery and other debris, the demo is complete and construction can begin. Everything was done by hand since heavy machinery cannot access the rear yard. Below is is photo of the crew lifting a 3/4 ton stump out of the ground using a portable crane.

This project brings us to Saint Francis Woods, where a major remodeling project has been taking place for almost a year. It started with the house being lifted off its original foundation, a basement level room being excavated, new foundation constructed, the house being set back down on the new foundation and interior remodel. An incredible job by the general contractor.  What you see below is the aftermath of such a construction project. Its a few days before November and Tamate Landscaping is challenged with the task of lowering the grade, erecting retaining walls, installing drainage, patios, pathways, steps, plants, irrigation, lighting and otherwise making it possible for the owners to move in all while racing against a possible wet La Niña season.

Completed Project: Retaining Wall Replacement

This project brings us to Baker Street in Pacific Heights where we are replacing a failed retaining wall that was installed just 15 years ago.  The project is a typical example of an architictural/engineering firms failure to design a project with construction costs in mind.  Since the client wanted to obtain building permits for this project,  she hired Smith Engineering in Oakland to draw up plans.  Once the plans were complete, the client proceeded to obtain several estimates for implementation.  The estimates that came in were astronomical and out of reach for the client due to the nature of the design and the plans abandoned. Thats when Tamate Landscaping was called to discuss options.   The original plans called for massive steel i-beams, timber and an elaborate sump pump drain system.  Yes, it would have been a solid wall that would hold up 50 plus years.  But any design is a failure if it can’t be built due to budget constraints.   Basically we had to start from scratch and draw new plans .  We ended up working with our own architect/engineer who has extensive experience working with San Francisco Department of Building Inspection as an employee there.  We designed a wall that would pass DBI’s stringent permitting criteria but more importantly could be built within the clients budget.  The outcome was a wall that we contracted to build for approximately 1/3 the cost of the original design.

Pictured here is the failed wall bowing out.

Demolition and excavation.

The main foundation of the new design are these 6″x6″ posts that were sunk in a hole in  excess of 4′ deep and 18″ wide and back filled tons of concrete.

September 28th, 2012.  The end of the 6th day on site.  Pressure treated planks were secured to posts with 1/2″ bolts.  To date we used almost 4 yards of concrete just to set the posts.  This wall won’t be budging for quite some time.  Next week we’ll be adding a Mira drain system to keep hydrostatic pressure off the wall and finish the project with a redwood fence and final inspection..

Below, a Mira Drain system is installed.  Basically, Mira Drain is a multi layer membrane with channels in between to allow water to stay of the retaining wall and travel down towards the base of the wall.  Typically, this water is then collected by an additional drainage pipe and directed out of the vicinity but in this case, with the sandy soil, is readily absorbed into the ground.

Project is completed by backfilling the ditch and building a redwood fence on top of wall.