The Root of the Problem

Truss uplift happens because the exposed truss lumber in an attic space absorbs moisture. This acceptance of moisture causes the lumber to swell. The swelling lumber lifts the horizontal bottom chord of the truss causing it to bow upwards in the middle of the truss.

Where does the moisture originate? Are we going into another ice age, with winters that drench us with above average precipitation and humidity? Does this humidity seep into the attic because of the new-fangled soffit and ridge venting? The answers to both questions are maybe. However, the source of the problem, I believe, has nothing to do with outside humidity. The outside weather has been fairly consistent for many years, at least as long as we have been using trusses.

I believe that truss uplift is directly related to the fact that we are building houses with tight windows and doors, superior vapor barrier systems and air infiltration barriers. The moisture that used to leak out around openings and through walls now has only one escape route - the attic.

What To Do?

I certainly am an advocate for building tight houses and saving energy. To do otherwise wastes precious resources for future generations. I feel the solution lies in correctly identifying the problem, and coming up with a workable solution. Fortunately in this case, the solution is easy.

Truss uplift will continue to plague houses. As we use lumber that is younger and less dimensionally stable, the uplift may even intensify! Minimizing interior ceiling and wall damage can be accomplished by simply allowing for the truss movement. In addition, maximizing flow-through air movement in attic spaces will allow moisture absorption into the exposed lumber to be minimized.

Simple Hardware & Blocks

You can purchase simple metal L-brackets specially designed for attaching interior walls to roof trusses. They cost less than 50 cents apiece! It usually takes about 15 seconds on average to install one of these simple clips.

The L-brackets have a short leg about 1.25 inches long that sits on top of the wall. This leg has two holes in it that accept nails. The other leg of the bracket is about 2.5 inches long. It has a slot that runs lengthwise up and down the leg. A nail is driven in the center of the slot. The bracket holds the wall in position while allowing the truss to move up and down freely.

Drywall Hanging 101

To solve interior ceiling problems, drywall hangers must also be educated and part of the team. We know the truss will flex. As such, we can't allow the ceiling drywall to be attached to a truss within 16 inches of any interior wall. What keeps the drywall in position and constantly contacting the top of the wall? You have two options.

If you have scrap 2x6 lumber, you can cut blocks that fit between the trusses and overhang the top plate of the interior 2x4 walls. These blocks are nailed securely to the top of the walls, NOT the trusses. As the trusses move up, the blocks retain and hold the drywall edge flush with the top of the wall plates.

If lumber is too precious on your jobsite, you can use very inexpensive metal clips designed to retain the drywall. These clips cost less than 15 cents apiece and attach with small 8 penny common nails.

Repairing Truss Uplift Problems

If you're building a new house, inspect your trusses. They should not be nailed to a wall using 16 penny nails. If you see nails, they must be pulled and the special truss clips installed in their place. The walls need to be attached to the trusses so that they do not fall over.

When you need to repair trusses in your home, be prepared to be in a very grumpy mood. I just wanted to warn you. You will want to kill the rough carpenters who framed your house. The job is miserable, especially if you try to tackle it in the summer.

Existing House Problems

There are hundreds of thousands of existing houses that suffer from truss uplift. I saw it firsthand, for the first time, six years ago. I did not realize at the time what exactly was happening. I did determine by questioning the homeowner that it was a seasonal problem with cracks being the worst in February.

To achieve the best results, the job must actually occur in two phases. You need to release the trusses from the walls and reattach them with clips in the dead of winter. Then the summer months will find you installing the drywall clips or wood blocks that will hold the ceiling drywall tight to the wall drywall.

In the dead of winter the trusses should be bowed upwards. There should be a small gap between the truss and the top wall plate. If you are lucky, the gap will be large enough to easily slide a hacksaw blade between the pieces of wood. Cut through the nails holding the truss to the wallplate. Be on the lookout on both sides of the truss for electrical wires! An easier method may be to pull out the nails using a special tool called a cat's paw.

Once separated, the trusses need to be reattached to the walls with the special L-brackets. When attaching the truss clips, be sure that you drive the nail through the center of the slot on the leg that points upwards. Don't nail too close to the bottom or top of the slot. In addition, the drywall that is attached to the trusses near the walls needs to be released from the corners where walls meet the ceilings. You can do this by installing the 2x6 blocks in the summer months when the ceiling has settled back into position.

You can now safely install the drywall clips and retention blocks between the trusses. If you try to do all this work in the winter, you may crack the drywall as you beat it down to the top of the walls.

The following winter, nail pops will appear at each interior wall where a truss passes overhead. The nails need to be countersunk into the trusses to complete the job. Use a large, flat nail set to drive the nails up through the drywall into the truss.

If you do not do this, the patching compound you use to deal with the fresh nail pops will be pushed from each nail pop the following summer. As always, the time required to solve a problem far exceeds the time to do the job right in the first place. Fortunately, in this case, the work required is not too difficult. It simply is spread out over a period of months. Be careful working in the attic. Don't fall through to a room below!

If you are a gambling person, you can try to do all of this in the winter months in two weekends. Test an area of the ceiling first to make sure you are not cracking the drywall. If you can do the entire job in one phase, consider yourself lucky.

Truss Uplift Hardware

What's more, both companies make a special little clip that attaches to the top of the interior walls. These clips restrain the drywall and allow it to stay in contact with the wall drywall as the truss moves up and down. I highly recommend that you look at the web sites of both of these companies. You will be amazed at the wonderful metal hangers and brackets they have. These are framing connectors you do not ordinarily see in hardware stores.

Check out the wide variety of metal clips that will make your next home improvement job a breeze. For example, have you struggled with building a sturdy shelf in your garage? If you have exposed 2x4's it is as simple as driving four nails! You will find there are heavy duty shelf brackets made just for this purpose. Workbench building is easy too. There are special brackets that allow you to bang a sturdy workbench together in a few hours!

Truss Uplift Literature Resource Materials

The following magazines and associations have a multitude of articles, research papers and press releases concerning truss uplift. The associations will undoubtedly help you, although there may be a fee involved for some of their publications.

Magazine: The Journal of Light Construction

Associations:

They have a two page document titled Partition Separation Prevention and Solutions, available for free download.

Metal Ceiling Manufacturers

Not all patterns are available through all companies. I guarantee you that you will find interesting, authentic, and attractive products on the web sites. The solid brass and chrome panels will take your breath away.

Be sure to use your imagination when viewing the photos. Think how some wall panels might look in a hall powder room. Imagine ceiling panels that are spaced in-between wood beams in a study ceiling. Do you have a modern trayed (multi-level) ceiling? Imagine using the metal panels on one of the levels or as a border. Remember to keep in mind the scale. If you intend to use the panels for a kitchen backsplash, try to stick with a smaller pattern that will repeat within the 16 to 18 inch area commonly found between countertops and long wall cabinets.

Here are the two manufacturers that make panels from the original dies. They have a huge assortment of products.

• W. F. Norman Corp.
  
• Shanker Industries, Inc.
  

The following company created dies of their own to recreate older patterns and some modern ones:

• Chelsea Decorative Metal Company

The following two companies are stocking distributors for Shanker Industries panels and trim:

• AA - Abbingdon Affiliates
• Chicago Metallic Corporation
  Chicago Metallic is the company that makes the "Slim Grid" system that allows you to install stamped metal panels in a suspended ceiling. They also make a completely hidden suspension system as well.

The following company offers 24 unique panels in 6", 12", and 24" styles:

• The American Tin Ceiling Co.

Other ceiling offerings:

• Entol Industries has Tinn Type
• M-Boss Inc. 'Tin' Ceilings.
• Pinecrest Metal Walls and Ceilings
• USG Interiors

Metal Ceiling Patterns

The following illustrations are examples of some of the intricate patterns that you can purchase. There are literally hundreds of patterns. Some are 100 year old patterns made using the same steel dies from the last century! Some are more modern. Remember that there are all sorts of accessory pieces. You can get different filler patterns, cornice or crown moldings, inside and outside corners, center medallions, etc. If you are the slightest bit creative, you can create a stunning ceiling. The illustrations below are courtesy of the W. F. Norman Corp.

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Time Has Stood Still

Based upon the response from people who read my column about metal ceilings, I am convinced that many people thought that the ceiling panels were unavailable. I have to admit that until I did the research for the column, I didn't realize that many of the original dies, used over 100 years ago, were still in use! Two companies are still in business that made the metal panels nearly one hundred years ago. In fact, one of the companies - W. F. Norman - still prints its 1908 catalog! Talk about time standing still in an industry. That surely must take the record here in the United States.

Multiple Uses

The restaurant industry is partially responsible for the renewed interest in metal ceiling and wall panels. Several national chain restaurants use metal ceilings. In fact, I was in one not too long ago that had thousands of square feet of metal ceiling in place. It looked fantastic in the bar area. I was eating dinner at the bar because the regular tables were full. Seriously, you can ask my wife!

I happen to like the metal panels when they are used on wall surfaces. If you choose a pattern that compliments your tastes, you can add a nice touch beneath a dining room chair rail. Metal wall panels also look smart inside of first floor powder rooms or in a basement family room. The facing to a family room bar will really look snazzy with metal wall panels in place. Perhaps the most innovative use is a kitchen counter top backsplash. Several photos show this in the brochures and booklets that I received while doing research for the column and this Bulletin.

Installation Tips

You need to keep in mind that the metal panels are just that. They are primarily steel or in some cases tin plated steel. This means they can rust if exposed to water.

Each manufacturer provides you with detailed painting instructions should you choose a material that requires priming and a finish coat. Always paint both sides of the ceiling panels, trim, cornice, etc. Remember water can come from a roof leak, plumbing leak or an accident from above!

Pay close attention to instructions regarding mill oil removal from the steel. Some steel mills coat rolled steel with an ultra-fine layer of oil. If your panels have this oil, paint will not adhere readily. Don't forget that water based primers can NOT be used to paint bare metal. You can often coat the panels and trim with water based paints once an oil primer has dried.

Attaching Panels and Trim

Metal ceiling panels are attached to furring strips in many instances. The spacing between strips, the shape of the strips, width of the strips, etc. are all a function of the pattern you choose. Each manufacturer gives clear instructions on what to do. Do not bother to install your furring strips until you have selected your material. You could make a big mistake!

Furring strip layout and installation is critical. The metal panels are precise. If you do not center your strips correctly or you install them with humps and dips, you will be able to see these defects when your ceiling is finished. Be sure you take your time with the furring strips!

Suspended Systems

Do you have a standard suspended ceiling in your office or basement? Did you know that many of the metal panels will fit into the grid system without any trimming? In fact, you leave the fiber panels in place to keep the panels from "lifting" when a door is opened.

If you want a really sleek installation you can choose a slimmer grid system or an invisible one. The invisible grid accepts metal panels that have a turned up edge. The metal ceilings that install in this fashion can look seamless if done correctly.

Check out the web sites of the manufacturers listed in this column. You will be amazed at the selection of patterns, trim pieces, accessories, etc. If you choose to use this material, you will not regret it.

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