Load bearing in living spaces part 1

The most common mistakes on buildings are not calculating out live and dead loads of buildings.

Lets look a living room, it has a large rug, 1 large couch, 1 love seat, 2 chairs an old style piano as well as some tables lamps books etc. the items listed is called live load because it can move into different parts of the house.

Lets look at the floor, it consists of oak wood floor, and under this floor is a sub floor. These to floors are called dead load they cannot move.

The room size is 144 sq. feet with a total live working load of 5760# we have over 2200# of furnishings lets say its Christmas and time for pictures 20 Light weight people have just overload the floor system.

But that was just for a couple of minutes well lets look at the dining room for 2 hours you have overload the floor system in there.

Lets look at the office paper is a lot heaver than people, a small 2 draw filing cabinet can hold up 960# of paper + he cabinet.

Most people have a few large filing cabinets as well as desks and chairs, printers, copiers.

The minimum for home construction is 40 live load, and for an office is 150# live load so by putting an office on a wood floor system is wool fully over taxing flooring system.

Look a baby grand piano it ways over 1000# setting on 3 points on the floor than add people around the piano and again you over taxed the floor.

Now your loads and what you are going to use the rooms for before building house.

Trussed roof vs. hand framed roofs

Truss roofs have a lot of benefits going for them. They are manufactured and dropped on site for installation. They can span great distances as well as having many different configurations; from a low pitch to extreme pitches as well as having vaulted ceilings barrel ceilings or stepped and pan ceiling all these can be incorporated into a truss.

Trusses give you a basic frame work to build from Trusses in and of them selves are great for a track house slap them up and install the roof sheathing than your off to the next job site.

On a custom home trusses are like a beams we use for a bridge it in no way follows the finished shape of roof structure.

Example if you want a pan, barrel or even a vaulted ceiling a lot extra framing must be done to get the finished look.

As is true on the exterior, they don’t make dormers in trusses or any type of valley all these types of decorations are all hand framed above the trusses.

The draw back with trusses they don’t give you a perfectly flat surface to install your roof sheathing or sheetrock onto. The most trusses very 1/4”-3/8” while I’ve had some come out that were off by 3/4”.

Now what can we do by code we can not cut them so we have to strip the rest of the trusses up to the height of the highest truss. A lot of extra time because some one was lazy at the truss plant.

The truss plants say there is no deflection in there trusses.

But I’ve seen on a 26’ girder truss holding up a hip set, have a deflection of 1/360 or over 3/4” pushing the interior wall down that had no load bearing below them cracking the sheetrock and racking the interior doors to the point I had to cut the top of the door so it would close.

The nice thing about hand framing you have flat surfaces to work with you can modify and rafter, or roof jack as you go.

The down side you are limited in span as to thickness of the lumber that’s being used.

Stairways

There are many different ways to look at a stairway:
Layout- A draftsman laid out with a couple of lines on a print saying where the stairway goes.

First lets look, does it fix in the opening from the finish floor 2nd floor to the finished floor on main floor (using an 8’ wall 9 1/2” joists carpet on 2nd and 3/4” wood on main floor sets the actual height of the stairs the code requires the tread height not more than 1/4” different in all the treads) the stair rise max. height set by the code is 7 1/2”.

Did the draft’s man draw in 15 rises, and 14 treads. The rise works out to 7.17 or 7 5/32” now lets see if the stairway hole is long enough, The code requires the tread to be 10”that make the rough opening 11’0” this size will just make the minimum head room height on the stairs.

Next let’s look on the print how wide is the stairway from wall to wall (the width) the code requires a 3’0” clear opening. This means you must frame the walls at least 3’1 1/4” for sheet rock and taping compound.

If the handrail is not removable than you must add the space from the wall to the rail plus the rail to the framed opening.

If the stair way has 1 or more landings or turns it’s in your best interest to make the stairway 8”wider to bring furniture and bed frames and mattresses up and down the stairs.

Another area you have to watch for is if there is a wood or stone nosing even carpet wrap under the balusters on the sides of the stairway if its on the side of the fixed hand rail you can ignore it.

If it’s on the other side of the stairway you must frame the walls wide to account for the 3’ clearance.

Why the 3’ clearance 1 haling in refrigerators, laundry equipment need the room as well an ambulance stretcher in case of an emergency.

Framing- When framing a stairway the landing at the bottom of the stairway as well as any 90°angle platform on the run of stairs must be at least as long as it the stairway is wide this is code.

Many times I have come to houses 1 and 2 years old and going down stairs to the basement and land IE concrete floor from the stairway to the concrete wall dead ahead was 30” or less this is not legal.

If the stairway from Sheetrock to Sheetrock measures 36” then that is what is required at the bottom of the stairway to the wall.

Next the code no longer allows the builder to hang the stair jacks on plywood they now have to be installed with metal hangers (like a joist hanger).

Using poor quality wood like spruce, pine or fir will in time create squeaks in steps; using a plywood beam like a micro-lam will stop these squeaks.

Lumber, and its markings

Lumber comes from trees and most building lumber comes from pine trees.

In the pine tree species there are 14 types of soft woods (pine trees).

In each soft wood there are at least 5 classifications of strengths of each type of wood:

* Select structural clear wood
* No.1 with small knots
* No.2 with knots 3/4″ and smaller
* No.3 with knots 2″ and smaller
* No.4 with large knots

More…
When the trees are cut into boards at the mill, they spray paint on the ends of the studs. The darker the color of paint, the better quality lumber you are building with.

Color ratings are purple, red, orange, light blue, and light green.

The darker the color, the better the lumber. Better lumber holds nails better, and the wood will not bow, twice, cup, or check as much as the lighter colors.

A lot of information but what does it mean?

What if your house is designed for Douglas fir floor joists and your contractor wants to save money and installs balsam or spruce floor joists instead?

The contractor changed your floor load rating from 17.6 lbs. dead load (furniture) and 60 lbs. live load (people) to 17 lbs. dead load, and 33 lbs live load — now your floor is not even legal.

I’ve seen it happen a lot.

Similarly, poor quality studs do a number on sheetrock — install it, and you can count all the screw and nail pops over time.

Roofing in Cold Climates

Roofing looks to be so basic

Did you know that the roofing manufactures will not warranty their products if the shingles are installed improperly?

The warranty does not warrant that your roof shall not leak. But instead they warrant that their product “shall not fall apart over normal weather conditions”.
More…
The contractor is responsible for the rest.

1. To make sure that the roof decking is structurally sound, solid and uniform (no damage, loosening, lifting or sagging), for a better roof deck plywood sheathing is better than Norboard/oriented Strandboard.

Moisture inside of the attic freezes on to the roofing nail on the attic side of the roof sheathing.
This moisture works on the Norboard sheathing.

In time the sheathing breaks down much quicker than using plywood sheathing.

What does this mean?

In about 6-10 years down the road when a high-wind storm comes your shingles are no longer fasted tightly to the roof deck and portion of your roof will blow off.

You say “No problem – insurance will pay for it.” and you pay a higher premium for that privilege and keep paying for years to come.
2. The code requires Ice & Water Shield to be installed 2′ beyond the inside surface of exterior roofs at the eve line.

The material is designed to keep water from getting to the roof decking.

The problem is the water sits between the shingles you see and the Ice & Water Shield.

Moisture on backside of the shingles makes the shingle break down and crumble leaving you with exposed Ice & Water Shield and gutter flashing.

Now the water is no longer going into the gutter in this area and instead is going between the gutter and fascia board and getting into your overhang.

Easy solution – install 15# tarpaper above Ice & Water Shield. It wicks water away from an area to a place it can evaporate.
3. The best way to make a roof last the longest is to keep the attic air temperature and out side air within 2° degrees of each other.

  1. This keeps the shingles from baking in the summer or creating ice dams in the winter.

    To achieve this, have a well ventilated roof.

    Continuous Venting in the soffits, and/or roof venting – as in ridge vents or metal roof vents. Gable end vents are great if you can in corporate them in the design of the building.