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Home Site Map - Steps - Foundations -

Prepare Site

 

Fence build site and protect

Orange fencing

Orange fencing is used to mark the perimeter of the build site.  This is way bigger than the house footprint but in my case is way smaller than the whole plot.  It needs to correspond with the building perimeter that is shown on your plot map drawing.  It is particularly important to make sure it clearly provides protection for any trees you want to keep and protect...

Fence trees to be saved

In the picture below you can just see the orange fencing round the outside of the build site.  The build site that is very much larger than the house footprint includes the entire area that will be disturbed by building activities, including where trucks park, where you will be changing the grade, and where will be cleared to create a lawn.  You should think in terms of never having to set foot beyond the orange fence.

House dite before starting clearing

Survey and approximately stake the land

Objective: Transfer drawings to real land

This is the process of transferring your house plot drawings to the actual land.  Particularly if the land is sloped, you will not be able to mark things accurately, but you need to try to get a close as possible.  Measuring distances assumes that the measuring tape is level or else you will be measuring a hypotenuse (which is a longer length).  You will need a bit of estimating and pragmatic judgment when measuring on a slope.

Establish basic location of the house 

The first thing to do is to mark the important setbacks.  In my case the most critical thing was the 100 foot building exclusion zone around the well.  You need to measure the 100 foot accurately to make sure there is no danger of the house (including its foundations) being less than 100 feet.  In my case the well cap was something like 18 foot lower than the house site so I fixed an 18 foot pole to the well casing and attached my 100 foot tape measure to the top of the pole.  This let me measure 100 foot horizontally.  I accurately marked the 100 foot circumference using stakes every 8 foot.

Other setbacks that may apply in your case include critical slopes, wetlands, streams, roads, easement roads, property boundaries, and possibly even the home of a rare animal.  Your local planning office will be able to tell you the required setbacks that are needed in your area.  For example in my area, a critical slope requires 50 foot of untouched vegetation plus an additional 15 foot that must not have a building, so the setback needed from the top of the slope is 65 feet.

Double check that you really have got all the setbacks correct.  It's better to be safe than sorry, so if a setback of 65 feet is required from the top of a critical slope then make it at least 67 feet to allow for differing opinions on exactly where to measure from.  A Well setback is typically 100 feet, but using 101 or 102 feet allows a safety margin.  In my case I made the western wall of the house just over 124 feet from the well to allow for a 20 foot wide deck (deck foundations must not be within the 100 foot Well setback area).

Once you have the setbacks marked then you know where you are allowed to build and you can decide where within that you want to build.

Establish the house orientation 

The next thing to do is decide which way you want the house to face.  Typically you will want to try to back the house south, but there may be other things such as a view that will influence the orientation.  Perhaps you want to have all the big windows aligned with a picturesque lake in the distance or a particular mountain.  Start by stretching a taught colored string from a stake in about the center of where you want the house to be, to another stake in the direction of the object of interest that you want to align on.  Look down the string to make sure it is exactly positioned right and adjust as necessary.  Note that it is not necessary for the string to be to the center of the house because it is assumed that the thing you are aligning on is far enough in the distance for the sight lines to be essentially parallel wherever within the house footprint you set them from.  The actual center of the house will be established by measuring from the various setbacks and reference lines relative to your plot map drawing.  This string is now the reference for setting the orientation of the house.  I call this the "North South" reference.

Establish north wall position

Now you need to establish another reference that sets where along the North South string the back wall of the house needs to be.  Here you need to take into account any things on the site that you need to be set back from.  In my case it was the septic system to the north of where the house will be.  I needed to allow for a septic setback, a driveway, then a slope down to where the house foundations will be, and then the border needed round the foundations.  Taking all this into account, you then position another reference string that sets the position of the north wall and is exactly perpendicular to the North South reference string.  The new string I call the "East West" reference.

Iterative process

All of this is in practice an iterative process and very much needs to be done in conjunction with your plot map drawing.  You should draw the two reference strings on your plot map and always keep the plot map up to date with any changes you make with the actual strings on the land.

It is useful to measure relative to existing buildings that are shown in the satellite photo.  This will help you match up the plot map with the actual land.

Plot map

You may discover things that you don't like about where you have decided to put your house and that may cause you to incrementally adjust the plot map.

 

Mark building edges and driveway with stakes

Once you have the two reference strings between stakes on the land and you have those same two reference lines marked on your plot map drawing, then everything else can be marked out with stakes from there.  For any stake you want to position, use the plot drawing package to find the distance from the two references and then go outside with a tape measure to find that spot on the actual land.

Use a nice long (ideally 100 foot) tape measure to measure from your reference lines.

Tape measure 100 feet

For stakes, I take 2x4s and rip them down the center with a table saw and then use a chop saw to make a point on the end.  This makes stakes strong enough to be hammered in with a big club hammer.  I needed more than 50 stakes to mark out my house and driveway.

On the plot map you should label key points of interest with letters (A, B, C, etc).  Typical points of interest are the corners of the house, the edges of the driveway, and the edges of any decking.

Plot building site

On the stakes, attach pieces of plastic (waterproof) "cardboard" (available from HomeDepot).  Write with a waterproof marker pen the reference letter and a few description words.

Letter labelled points from plot map

South east house corner label

Join the stakes with colored string

You want to make the house layout as clear as possible to help inspectors make sense of what you are proposing to build.  You should use colored string to join up the stakes to form the outline of the building and the driveways etc.

Colored marker string

Markers in the forest

 

Live the house

Having the house perimeter marked on the real land allows you to for example place a chair where the living room will be to see if you like the view.  You can pretend to walk in through the front door, then go into the dining room and even setup a picnic table there and eat your lunch.  Try to "live the house" to make sure you like everything.  Perhaps even invite some friends over and give them a guided tour.  Through this role playing, you might decide that moving the house a little to the left will allow you to get the view you want while also allowing you to keep a tree that you particularly like.  Making this type of change now just involves moving pieces of string and is a lot easier than deciding later to move concrete walls!

Get into the habit of walking down the driveways defined by the colored strings and if you find yourself tempted to take short cuts then ask yourself if the driveway really is in the right place.  The first users of the driveway to your house will likely be a very large truck with crushed stone and a very large concrete truck, so make sure that there is enough width and height clearance to allow for this.

Make sure you have the permit

You must not proceed past this point until you have a "Clearing and Grading" permit.  Without a permit, even if you were to just do some light pruning of trees and some brush clearing you run the risk of annoying the inspectors.  It's best to just leave the site completely untouched (apart from the fencing, the signs, and the string) until you have a permit.

Here is my permit (with the personal info removed)...

Clearing and Grading Permit 

Clearing and Grading Permit 

Clearing and Grading Permit 

Clearing and Grading Permit 

Clear trees

Save any plants

Before starting clearing, there may be plants in the house site that you want to transplant.  Even in the wild forest there are small tree seedlings as well as Sword ferns, Oregon grape, and Salmonberry plants that are worth saving.

Save plants before clearing

Mulch store

When clearing trees you will have a lot of leafy branches from your cutting.  These are useful for scattering over newly excavated ground to help prevent soil erosion.  You should form a pile to store it until it is needed.  Any left over in the stockpile will rot down to make compost.

Stockpile mulch

Felling the trees

Using a chainsaw, cut down the trees that are in the way of the building.  If you are not sure if a tree will be in the way then it's best to leave it standing for the moment (because you can't put them back if you decide you want them).  Cut the trunks into manageable lengths so you can transport them off the building site.  I used my jeep and my tractor to drag them away.  If you want them to be useful as lumber then try to keep the lengths greater than 12'6".  Keeping them long gives flexibility even if you eventually decide to cut them later into 18" lengths for fire wood.

House site clearing started

House site clearing part way through

Clearing for driveway

Gradually cutting big maple tree

Tree clearing nearly done

Tree clearing done

Site cleared

Tractor on site 

Get utilities marked

Free service

Before doing any digging it is important to know where any underground utilities are.  For public utilities this is a free service provided by the city.  They spray paint lines onto the ground.  You need to be particularly careful that you don't hit an underground electrical cable as that would be particularly dangerous and may land you up in court.  If you have a private Well and/or a septic then it's up to you to figure out if you are going to hit one of your own pipes.  Try to do some trial digging with a spade to find water pipes.  If you are not absolutely certain where the buried electricity lines are then turn the power off before digging.

Here's a trial trench I used to locate water pipes and electrical conduit...

Located water pipes 

Found water and electric pipes

After finding the pipes, mark the estimated path on the ground using colored spray paint.

Mark pipe locations 

Establish reference height for the excavation

Figure it out from your drawings and a laser level

On the plot map, draw a line that best reflects the direction of the slope, ie a line down the slope at its steepest point, perpendicular to the contours.  I call this the "slope gradient line".  In my case that happened to correspond to line from the septic system intake down to the position where I plan to put the sewage pump tank.  The slope gradient line is the purple diagonal line in the diagram below.

Foundation drawing

To establish accurately the slope gradient, place a laser level on a flat surface at the highest point and shine it along the slope gradient line.  Measure down from the laser line at the various points of interest to establish the existing grade levels.

Height reference laser 

Using a stick with a white piece of card on the end is a good way to be able to see the red laser dot.

Height reference stick 

Draw this on a cross section diagram.  Also decide what you would like the grade to be and draw that on the diagram.

Excavation profile

 

It is assumed that you want a flat house site.  The first stage of excavation will be to cut down to a level that will correspond to the top of the slab.  This is 2'2" below grade level.  In the diagram below (that shows the profile for the footings), the green line represents the new grade if you are not doing any backfilling (which is 2'2" above the site leveling excavation).

Excavation Heights East West (Cropped) 

Excavation Heights East West 

Here's the equivalent drawing I used for the evaluation building...

Excavation depths 

Dig an excavation reference hole

Find the lowest point on the plot where there will be a house wall.  If you have drawn the gradient line correctly, it will be the where the lowest point on the line cuts through a house wall.

Dig a hole at that point down until you hit good solid soil.  In my case I was looking for the level at which the "Light gray Tokul" subsoil started.  Certainly it wants to be well below any organic soil.

The bottom of the hole will be the reference point for the first phase house site leveling excavation.  You will be asking the excavator guy to make the whole house site be level with the bottom of this hole.

It is possible that you might decide to set the reference level a bit lower if there are additional factors.  These factors may include, bad soil conditions, a desire to sit the house lower for esthetic reasons, a desire to have the basement 51% buried so it does not count as a story, etc.  In my case I was happy to do it as per the reckoning described above.

Here is a picture of my reference hole...

Reference depth hole

Reference depth hole with tractor

I found it useful to expand the reference hole to become a trench along a section of the slope gradient line.  This corresponded to where the sewage and foundation drain will eventually run.  I made the trench bottom gradually slope down from the reference hole reference height so it acted as a drain from the house site.

Ditch from reference hole 

Reference ditch on site

Reference ditch inside

Remove the top soil

Save it for later use

Top soil will be very useful when you are creating flower beds around the house later.  Top soil is very valuable stuff because it takes nature a long time to make it.  You strip it off the house site and store it somewhere in your yard for later use.

Top soil removal with tractor 

Even though using a tractor to scrape off the top soil seems like a cool way of doing it, in practice most of the top soil in my case was done with shovels and moved with buckets.  A nice thing about doing it by hand is that you can be more selective about what is the best soil and you pick out the stones as you go.

Top soil carrying in buckets 

Top soil being removed 

The official way of doing it is with an excavator, but this kind of finicky digging can get expensive when you are paying $100 per hour.

Save top soil 

However you remove the top soil, you need to stockpile it in an officially designated place.  That official place should be marked on your plot map.

Plot drawing for building site

This shows the top soil pile just starting to be formed...

Top soil pile second day 

And here's the final pile, now covered in mulch to protect it...

Top soil stockpile covered in mulch 

You can also use tarps to cover your soil piles...

Top soil pile covered with tarps 

The following pictures show the site ready for excavation.  The good top soil has been removed.  Areas with poor top soil have been left untouched.

Top soil removed 

Ready for excavation 

Ready for excavation 

 

Excavate the site to level

In my case there was a huge amount of excavating to do.  I needed to take a hillside with a 1 in 7 slope and cut it flat over the whole house site and a bit beyond.  It needed a heavy duty excavator - a 120, which is the biggest you can move on public roads without needing the large cost of an exceptional convoy.

The excavator has wide tracks so you need a nice wide access road to the site.

Access road for excavator 

Clearly mark on the ground with spray paint the area that you want dug.  The clearer you make things the less time and money will be wasted.

Excavation spray paint line 

Excavation Day 1

Excavator arriving

Excavator starting

The first big job is to dig out the tree stumps.

Felling trees by cutting the trunk with a chain saw is easy (although great care is necessary to avoid injury).  The hard part is getting the roots out from the ground, and it is necessary to get the roots out from under the house area.  There are various strategies for getting the roots out, but most methods involve using heavy machinery ie an excavator.  If the tree is not too big then you may be able to topple it over (roots and all) by pushing on the trunk with the digger.  If that doesn't work then cut the trunk near ground level and dig around the roots with the digger until the stump is free enough to be lifted out by the excavator.

Tree uprooting 

Excavator tree stump digging

And move the stumps out of the way.

Excavator tree stump moving

Excavator tree stump moving

Starting the slope down.

Excavator starting slope down

The earth dug is formed into a mound that is gradually moved backwards.

Excavator making mound

While the excavator is doing its thing, you need to scavenge rocks and cart them off to a rock pile for saving.  Rocks are a really useful resource so definitely worth saving even though it's a lot of work.

Excavator getting rocks

Excavator on mound dropping soil

Excavator digging slope

Excavator on mound getting rocks

Excavator dropping soil

Excavator carrying rock

Excavator digging in slope

Excavator slope half done

Excavator extending slope

Excavator mound extending

Excavator more of slope

Excavator mound getting bigger

Excatator moving mound

Excatator digging bottom of slope

Excatator moving mound more

Excatator digging around

Excatator toku in hole

The following two photos are after one day's digging.

Excatator end of day 1 

Excatator mound after day 1 

 

Excavation Day 2

Excavator big maple starting 

Excavator big maple uprooting 

Excavator big maple carrying 

Excavator on mound dumping 

Excavator Toku 

Excavator on mound Toku 

Excavator Toku loose 

Excavator 360 degree laser 

Excavator western path in 

Excavator Toku digging 

Excavator end of day 2 

 

Excavation Day 3

Excavator on mound showing pipes 

Excavator scraping 

Excavator resting showing pipes 

Excavator end of day 3 

Excavator end of day 3 

Excavator end of day 3 

Excavator end of day 3 

 

Excavation Day 4

Excavation bucket close 

Excavation ring of cut 

Excavation cut from hole 

Excavation on mound 

Excavator end of day 4 

Excavation cut wall soil layers 

Excavator end of day 4 from mound 

 

Excavation Day 5

Excavator digging under conduit 

Excavator digging level 

Excavator digging mound 

Excavation view down from mound 

Excavation view east from mound 

Excavator side view 

Excavation end of day 5 

 

Excavation Day 6

Excavator uncovered rock 

Excavator digging south east 

Excavator moving rock 

Excavator moving rock 

Excavator moving rock 

Excavator moving rock 

Excavator danger sign 

Excavator end of day 6 

 

Excavation Day 7/8

The last day is mainly about getting the ground level by using a laser.

Excavator start of last day

Excavator on mount

Excavator south edge

Here is the site all nicely leveled...

Excavation finished 

 

My ground type

In my case the subsoil a few feet down is what's called "Light gray Tokul".  It is deposited by several glaciers and is sometimes referred to as "glacier till".  This is very solid ground that some people liken to concrete.  It forms a great base to build a house on.  With the completed excavation, the entire flat area is down to this Light Gray Tokul.

Toku soil 

 

Stabilize the soil

You need to avoid the soil being washed away when it rains or being blown away in high winds.  This is done by spreading mulch from your mulch stockpile over the soil or plastic sheeting soon after it is excavated.  Also scatter grass seed all over.  Transparent plastic over the grass seed helps it get started more quickly and in colder weather.  Once the grass starts growing you can gradually remove the mulch and/or plastic sheeting.

Plastic over earth mound 

Implement French drain along edge of site

Important to keep building site dry

It is a real pain if water runs through your house building site when it rains.  It can cause foundation trenches to cave-in, and sand and gravel to be washed away.  If your building site is sloped then ideally before digging the footings or at least straight away after you need to implement a drainage channel along the uphill border of the site to catch surface rainwater before it runs down the slope.  See details here .

You may also get water running out of the slope itself.  Water often flows in the different layers in the ground and you will be cutting through the layers.  It may well be necessary to implement a temporary drain ditch at the bottom of the cut slope if you find you have a water problem (luckily I didn't).

Drainage ditch with perforated pipe 

 

Keep excavation dry

The excavated area is a huge flat area with very solid soil, so it is going to collect rain water.  You can place a sump style water pump in a convenient place, connected to a hose pipe, and run it after heavy rain falls.

Water pump - sump style 

Sump pump in excavation 

 

 

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