Monday, July 31, 2017

Tips to keep you out of trouble

These days I am working with very old stone construction where I live...chestnut beams and tiles everywhere, But I have still to upload pictures of construction projects from the past.  Here is a bit of general advice when doing wood construction, till I can figure out a way to upload photos of other construction.

Use a framing square.  There are many times when you use a square, to make straight cuts on your 2x4s or on your plywood.  I am pretty sure that most people know those.  However, it is imperative to use it other times as well. When you gang several framing members together, such as when you add cripples to a framing member to support as window lintel or the bottom of a window.  You might think it is Ok to eyeball or use your fingers to determine if the bottom is level.  But it is so easy to run the ganged members uphill by just feeling that they are flush with your hands, and if you do it with one, several ganged together will really go uphill.  Use the square to make sure the bottom of the column is level.  This is true of corner posts as well.

When you put blocking between floor joists to make nailing surfaces on sheet good or board seams, or if you put in blocks to keep joists from twisting, make sure that they are not too tight.  you can easily bow the entire joist out of straight by just forcing one block in that you have cut a 16th too long.  If you continue to do this, you can multiply the problem each time till you are way out of straight and no longer can match up seams going the other way.  The only remedy is to take the blocking out and start over, or sister new beams onto the joists so that the edge of the sheet goods land on a joist.

Don't allow a mistake to go unrepaired as you are doing the lower parts of a building.  as you work on the building, the mistakes show up as you try to fit the walls, and roofing together and they can get to be bigger and bigger headaches as you continue to work.  Take it apart when it happens even if it is difficult...correct it and start fresh.

Use the proper nails.  Get advice from the lumber yard.  Tell them what you are doing and have them advise you as to guage, length material and special texture of the shank or head.  There are nails for decking, roofing, laying floors, shingles and clapboards.  Choose the right one.

Choosing between nails and screws is another personal issue for me.  When I am working where there is no electricity, it is hard to use screws, and I hate battery operated tools!
One thing I have to say in this age of sheet rock and similar screws, is that nails have great tensile strength.  They will take a lot of twisting, wind movement and walking over, before they will break.  Screws tend to be a bit more brittle when they are bent a couple of times.  When the wind buffets your hose a lot, it is not good to have metal fasteners fail from metal fatigue.  Nails do have a weaker hold when you try to pry members apart, but if you choose the right nail that is large enough to do the job, I find them better in many ways.

Use diagonal metal straps to help reduce sway and racking in your building.  This is essential....DO NOT OVERLOOK THIS... when you build with boards, even tongue and groove or ship lap boards.  Sheet goods such as plywood, Oriented Strand Board etc., will do much of this job for you, but it might be wise to do diagonal bracing anyway, in case metal fasteners or even the wood itself around the fasteners and on seams fail in time from repeated movement. Use the braces horizontally in ceilings, rafters, on roofs, floors, and vertical places like in all walls.  This is very true if you are using a purlin system for your roof
, like in metal roofing.  They are very cheap, and though they may prove to be redundant, it will not bankrupt you to be sure.  This is extremely important in buildings with very large openings in the walls, like screen houses, open pavilions and buildings with large windows and doors.

One thing you might not realize when working in these days of standardization.  You need to check your lumber before using it.
It is not unusual to find that your 8 foot long 2x4 is 8 feet 1/2 inch long, or 7 feet 11 1/2 inches short...so to speak.
Measure every piece of wood that you use.  Lumber is often a little long or short, and this can be a nightmare if you have constructed something complicated and find that that last piece of wood just does not fit, because three other pieces that you assumed were a standard length....WEREN'T.
This also goes for the dimensions of the lumber...your 2x4 is supposed to be 1 1/2 by 3 1/2 inches.  But sometimes this is not the case...again...to late to fix it after the construction is almost done.

Also, check your sheet goods....you may be planning on using a sheet of plywood only to find that it does not fit because it has tongue and groove or lap cuts.  Your piece may be 4 feet wide, but do you have to overlap or fit the tongue into a groove to make a slight difference, or it might be a bit wider that you expect. 

Friday, March 3, 2017

Gimme Some Air! Mold Problems

In the olden days,when I was young, there was a sort of rule of thumb that the entire volume of air in a building should be exchanged  or replaced every 8 hours.

  No one stood there with an instrument to check this out.  There were no such instruments. However, with the construction techniques of the time, it was likely that no seal against the outside air or sealing the inside air in would have been possible anyway.

The advent of vinyl and aluminum siding sealed many a house up and promoted wet insulation and mold growth. damp air passed through the walls into the cavities and was stopped by the siding. Venting the siding helped but did not stop this problem.

  There were no vapor barriers.  There were few sheet goods.  Plastic was new to the markets and unused when it was.

In the center of the photo you will see a trial spot where chemicals were tried out to remove the mold. Here is a building that I worked on.  It was clad in Aluminum, then later capped with a metal roof.  It was sealed up tight as a  tuna fish can.  Then the mold started as the basement was damp.
 
 
Walls were built of separate boards, and few would have bothered, unless there was a lot of money involved, with tongue and grove for sheathing.  Floors were rarely insulated, and many times the walls and roof were not insulated either.  Sometimes you used saw dust, which would get wet and pack down to the bottom of the cavities that they were meant to insulate.  Early houses had cavities that were filled in with brick and mortar, sometimes there were woven sticks plastered over with mud or plaster, sometimes left over from the first year where that was all there was for walls. Those too would develop cracks  and allow air to pass through.

 
 
I believe that where people were using the almost endless supplies of wood that were cut for fields and roads, they were much healthier than they might have been because of the exchange of air in rooms that had smokey fires.
 
Also, I think we were much healthier when there was this exchange of air even up to my high school days, when plywood and heavy insulation with vapor barriers appeared in houses.
With a space heater heating a small space, a gas heater, small wood stove, a gas range, etc., it is necessary to let air into the house.  First they need air inside to combust the fuel, and second, the inhabitants need air to replace what air the burning fuel consumes.  Carbon monoxide and carbon dioxide are not the only people and pet killers in a confined heated space.  Once a flame dies from oxygen deprivation and the fuel does not stop, there is the plain gas still coming in.

Of course we use gas and smoke detectors to warn us of these killers, but still, there is enough of these gasses in a small space to be uncomfortable, to be constantly smelling the air up and to make a very unhealthy environment, especially since we, too, exhale CO2 and consume oxygen. Our plants may love it, and provide a bit of oxygen, but it truly is not enough.

So you can choose to build lots of air leaks into your envelope, fill your house...literally... with house plants, smother in one of may ways in your small space or be constantly awakened by buzzers in the night.

I do not really have an easy solution to this impossible choice.  Bring outside air in with an air vent and use outside air to combust your fuel....but is this really enough to be healthy in a small space?
All of this became critical when Jimmy Carter was in office, and fuel shortages became the norm.  We buttoned up the houses at that time, and air simply does not easily come into your house anymore.
 
Another unexpected byproduct of this tightening, is MOLD!  Some molds will not exactly kill you, but they can be awfully unpleasant, especially if you are sensitive to them.  Spores go everywhere, and soon your walls and possessions are covered and often stained by the mold beyond recovery. Those few deadly forms must be promptly treated professionally, and can often put you in the position of having to find alternate places to go and burning or scrapping the materials infected and indeed, possibly the entire house.

Dehumidifiers will help. If you have no electricity, you can get the dryers that are available in grocery stores and hardware stores that attract moisture to a chemical.  Some drop the moisture into a reservoir and last much longer especially with refill crystals.

Wash mold with chlorine or chlorine based products immediately, and always be on the lookout for it in corners, and in blind spaces like cabinets and closets...We are so fond of these in tiny houses!

Drill decorative holes in doors...clover patterns are easy with a bit and brace or electric drill, hearts are traditional, as are flowers and their stems and leaves along the seams between boards, using the seams as the stem of the flower. This will help air to circulate a bit.  Leaving doors ajar will help as well.
 
Tiny computer fans that consume very small amounts of energy will help to circulate drier air into these spaces.
 
It is hard to pack these spaces with our possessions and still get air circulating to all the surfaces.  The Damp-Rid crystals will help. but may not be enough.

If you get a leak from outside, or have a corner where there is no air circulation, you are almost certain to get mold or mildew.

Another issue is absorbent materials.  Carpets in storage spaces are a real no no.
Clothing harbors mold, unpainted wood or plywood absorb moisture...Paint them.
If you do get mold and clean it off unpainted wood, paint it to seal it up. Cardboard boxes will absorb moisture and promote mold growth, but plastic will seal moisture in to a box and promote mold inside, even if it WILL keep mold from growing on the outside in a storage place. Let in all the air you can, but stop the water from coming in....now how do you do that????

You cannot make your house clean enough to stop mold!

Using those vacuum storage bags for all soft and absorbent articles will help immeasurably, but make certain that anything put inside is BONE DRY!

Do not cram your spaces full.  Allow air to circulate in all spaces.

Remember, that mold spores are everywhere...you cannot eliminate them in the air, the soil, on pets and on you!  You must be vigilant and watch for signs of mold and for places it may be starting, unseen.  Be aware of smells and coughing or stuffy noses in your house.
 
Gas heat is notorious for putting moisture into the air, as there is lots of moisture in the gas.  If you have it, or NOT TOO DRY WOOD heat, you must be doubly vigilant and should start the heating and cooking(steam trapped in the house from your tea water and the moisture from a composting toilet is pretty bad too.) season in your sealed up house is the time to start the drying inside the house.
 
Summer, as the mold grows above 45 degrees, can be awful, as the mold loves the warm and humid summer air.

If you live by the sea or a lake, make checking for mold a daily activity!

Mold is much like the barbarians on the borders of Rome....you may keep them at bay, but they will never be defeated.  The only remedy is constant vigilance.