EXTERIOR PAINTING RESTORATION

, ContractorMagic Brush, Inc.

San Francisco, California

Abstract: The repair and restoration of deteriorated wood siding, trim, and ornamental plaster on the exteriors of older buildings is one of the cornerstones of what is called a “Painting Restoration”. From the symptoms of paint failure, one can determine the underlying causes, and then decide upon the proper cures.

INTRODUCTION

It happens time and again. A simultaneous cheer and sigh of relief go up in the neighborhood when the funkiest house on the block finally gets a new paint job. Yet, within a couple of years, the seams start popping, the paint starts peeling, and trim elements come loose – the “face lift” begins to fall. It does not have to be that way, but in order to forestall the effects of sun and moisture on painted exterior surfaces, one needs to understand the causes of said paint failures, and then how to treat them. Although the techniques discussed in this article were developed on older wood buildings, they can be applied to other types of structures.

A “Painting Restoration” is first and foremost an Attitude. It determines the approach one takes to the work to be performed. Most painting contractors are trained to recognize and treat the surface conditions of paint failure. But these are often only the symptoms. Left untreated are the causes. All too often, if the painting contractor does not take care of these conditions, they do not get taken care of at all. The result is a short-lived paint job – one that does not serve its true function.

The Procedures involved in a “Painting Restoration” can be divided into Four General Categories:

1. Treatment of the existing paint film: e.g. stripping, general preparation, etc2. Treatment of the underlying surfaces: e.g. repairs, replacement, epoxy fillers, etc.3. Primer(s), caulking, cosmetic fillers, etc.4. Finish coat(s)Of course, all four Categories are equally important. The success of the paint system depends upon all elements being performed correctly. Any “weak link” can result in the failure of the whole system. It is the contention of this author that the least understood Category is #2 – Treatment of the underlying surfaces. This is the cause of many of the premature paint system failures that are often observed in the field. This article will principally address the identification of these problems and treatment of these surfaces, while touching on related elements in the other Categories.

IDENTIFICATION

The causes of exterior paint failure are interrelated. Many buildings suffer from several problems: some have been neglected, the existing paint film may be old and dried out, previous paint jobs have not adequately treated small problems thus resulting in larger problems, etc. Wood buildings are subject to enormous stresses, due to heat, cold, humidity changes, rain, and ultraviolet waves. In response to these stresses, the wood moves- it flexes, expands and contracts. Most pre-1970 buildings possess one or more old layers of oil or alkyd paint, which are relatively inelastic. The wood flexes, the paint film does not, and surprise- you have peeling, crazing, and alligatoring paint. Other conditions contribute to failure: previous painting over a dirty or chalking film, salt accumulations, moisture trapped from inside, or just plain poor workmanship. Another significant cause is the inadequate treatment of problem conditions that underlie the paint film- conditions we have chosen to designate as “Category 2”. This involves identification and treatment of the wood itself (or of whichever material the substrate may be). These procedures most commonly include: removal of rusted nails, resecuring loose trim, fabricating new moldings where needed, proper treatment of pockets of non-structural “dry-rot” with epoxy consolidants and patching materials, removing old patches and fillers, making windows operational, inspection of gutters and downspouts and other sheetmetal for signs of rust, as well as examining all surfaces in general to establish possible areas of future concern.

The initial assessment, usually performed while preparing the “Painting Restoration Proposal” for the owner, should differentiate the various types of paint failure found on the building. With older buildings there are usually several types, most commonly: A. Failure due to old “tired” paint – e.g. Alligatoring and crazingB. Failure due to inadequate bonding between coats – e.g. intercoat failure (Often the

result of painting over glossy surfaces that have not been etched. Also caused by painting over dirty or salt accumulated surfaces.)

C. Failure due to moisture trying to escape from the building – e.g. leaky roof, blistering

D. Failure related to the condition of the underlying surface itself – e.g. “Category 2”

The conditions related to Items A, B, and C above basically impact how much surface preparation will need to be performed on the existing paint film. Some areas may require total paint-film removal, and the method of removal will have to be decided (heat, chemical, machine and/or scraping). The presence of lead must also be assessed and accounted for. The decision of how much to strip vs. scrape/sand is not always an easy one to make. It involves balancing long-term performance against the owner’s Budget. Stripping is generally far more expensive, as it involves not only the additional time spent removing the old paint, but also additional caulking, filling, and more coats of paint. How does one decide whether to scrape/sand or strip? Like many decisions that have to be made in the building trades, the right call is a

combination of past experience and intuition. If half of the paint on the siding of a building that faces the weather is alligatored and crazed, it is a safe bet to assume that the other half is questionable and should be removed as well. Paint that shows stress cracks that run perpendicular to the wood grain is generally more deteriorated than paint with cracks that run with the wood grain. Extensive blistering almost always indicates a surface that should be stripped entirely. Experienced painting contractors are familiar with all of these conditions and the “solutions” to them.

The conditions related to Item D above (what has been and will hereafter be referred to a “Category 2” conditions) basically impact work that needs to be done to the underlying surface itself. Identification of these types of conditions/surfaces is usually not difficult. Many clues exist on older buildings. Experience is, of course, the best teacher. Examples of conditions to look for include: loose moldings, honeycombed plaster, rust stains, deformed wood (especially surfaces that should be flat), window sills with splits and/or indents, old patches, water stains, missing trim elements and the like. All of these signs indicate underlying problems.

PHOTO: example of decayed moldings

Many of the causes of such failure are neither correctly identified, nor treated properly by most contractors. For example, one of the most common conditions we encounter is evidenced by old nail hole putty sticking up above the surrounding surface. The putty is usually loose, and most painters will scrape and remove it, and then “treat” it by putting more filler in its place. The result is almost inevitably that the “new” putty will soon be working its way out of the nail hole. Why? Because only the symptom was treated – the cause was not. This condition is almost always the result of rusted nails AND the concomitant deterioration of the wood surrounding the nail. We generally refer to this condition as “dry-rot” (although in some cases it

technically may not be such). It is not uncommon to find hundreds of nail putty “pops” on a Victorian façade. The nails securing siding are common locations, as are trim components. Windowsills and ledges are also typical locations for discovering rusted nails surrounded by deteriorated wood. One can often dig some of the wood out with one’s fingers. Is it any wonder that new putty will soon fail if something is not done about the wood itself?

PHOTO: Easily observed indications of failing putty, rusted nails and likely dry-rot.

PHOTOS: Digging out the rusted nails and loose decayed wood is very important prior to restoration using the epoxy consolidant and epoxy filler.

WHAT TO DO

Deteriorated wood (and plaster as well) can be treated by two techniques: replace or repair. Unless a building element is badly compromised, it usually can be saved – we refer to this as being “Restored”. Two products allow us to restore most deteriorated wood and plaster surfaces. The first product is an epoxy consolidant- a low viscosity liquid designed to stabilize affected areas. The second product is epoxy filler – sometimes also referred to as a fairing gel. It is used to fill voids and reconstruct missing detail. These products enable one to repair virtually any damage, as long as there is some integrity to the piece. However, if the building element falls apart in one’s hands, well, replacement is warranted.

The use of these products can produce nearly permanent repairs. Restoration is also generally less expensive than replacement of most moldings and detailed elements. One area that many owners frequently ask about is their windowsills, which often are in poor condition. Many times, the owner is convinced that they have to be replaced, at great cost and inconvenience. This is, in fact, rarely true – almost all conditions of this type can be successfully and long-term repaired with the proper use of the epoxy consolidants and filler.

ConsolidantsThe first step is to remove the old loose filler, the rusted nail(s) and most of the deteriorated, “punky” wood surrounding the area. This can usually be done with a “teardrop” blade scraper. The resulting hole is generally between the size of an almond shell and a walnut shell, but can sometimes be much larger. One does not have to cut back to 100% sound wood, because the consolidants helps rebuild weaker wood fibers. After resecuring the element, small holes ( 1/4” typically, depending upon the size of the piece being restored) are drilled all around the deteriorated area. The holes are usually from ½ to 1 inch apart. This allows the injection of the two component epoxy consolidants into the endgrain of the wood, with draws the consolidant into the looser punky wood sections. Plastic ketchup and mustard bottles can be used for this operation. On larger, flat surfaces like windowsills, the consolidants are applied by brush, thoroughly saturating the area. This procedure is repeated several times on each area- filling up the drill holes and/or brush applying the material, until it is observed that no more consolidant is being absorbed.

Some of the consolidants on the market are so thin that they have virtually no film build at all. Others are thicker and some even have adhesive properties. Our preference is for the thinner products, as they are probably absorbed further through the end grain. The consolidant is absorbed through the wood into the affected areas, where it encapsulates the wood fibers, stiffening them to allow acceptance of the

epoxy filler that follows. Most old patch jobs fail for two reasons: 1. Use of the wrong material (most powder based fillers, spackles and automotive “bondo” are not good for this type of work), and 2. Lack of adhesion between the filler and the wood. How can a patch be expected to hold up if it is adhering to a crumbling substrate? This is why it is so important to look for and remove old patching attempts- they are rarely sound.

PHOTO: example of drill holes that allow epoxy consolidant injection.

Additionally, weathered wood that needs no particular repair is often encountered on older buildings. Sills, ledges, and rail caps are typical examples. This same epoxy consolidant can be applied to them as well. Why? Wood consists of cellulose fibers bonded together by lignin. The exposed surface of the wood consists of these fibers that are only loosely attached to the bulk of the wood underneath. This is true both for new wood and older wood, and especially true of weathered wood. Have you ever noticed that the backside of peeled paint often contains many attached wood fibers? In many cases, one can legitimately say that paint failure was actually wood failure.

This is a very interesting and instructive concept. Paint is often not adhering to a very firm substrate- it is trying to bond to relatively loose wood fibers. That’s where the consolidant fits in – it bonds the surface fibers into the more solid mass underneath, providing the paint primer that follows with a solid surface to mate with. The

consolidant can also be successfully applied to bare plaster. The looser, dusty surface layers are bonded back to the more secure substrate. This is very effective in promoting the adhesion of the paint coats that follow. This logic even extends into clear finishes. Some of these consolidants can be applied over bare or stained wood, and then varnished. The result is an exterior varnish finish that, in our experience, lasts twice as long.

Epoxy FillersAfter the deteriorated area has been treated with the epoxy consolidant, it is now ready to be filled. The fillers we have used are two component epoxies, with a 1:1 mix ratio and a working life of perhaps 30 minutes. About the only thing that can go awry with these products would be due to inadequate mixing of the two components. Our method is to scoop out two “balls” of equal size and place both into a large wiping rag, squeezing them together and then kneading the mix for about five minutes. Thorough mixing is necessary. Interestingly, the curing generates heat, and since a larger mass generates more heat than a smaller mass, and since heat accelerates the curing process, the result is that a larger patch cures faster than a smaller patch.

Once the epoxy patching materials are thoroughly mixed, it is applied with a putty knife to completely fill the hole. Before the epoxy start to harden, it can be bladed over with a knife that has been dipped in lacquer thinner. This smoothes out the exposed surface somewhat, helps in shaping, and minimized the need for subsequent sanding. Epoxy fillers shrink very little, if at all, because they cure chemically and not through the evaporation of solvents or other vehicles. Thus, most holes only have to be filled once. After it cures, the epoxy patch can be easily sanded, filed, drilled, nailed into, or shaped. This produces a nearly permanent repair, as it literally fuses with the surrounding wood, and flexes at a similar rate as the wood.

This flexibility is very important, because most other types of wood fillers fail because they are more rigid and brittle than the wood itself. As the wood expands and contracts with the weather, the filler cracks and allows moisture in, thus furthering the failure of the patch. The epoxy fairing gels are designed to flex with the wood.

If the area of repair is very large, a piece of shaped wood can be used to partly fill the void. As long as the piece of wood is completely surrounded by the epoxy, the patch will hold up exceedingly well.

It is also useful in some cases to use nails or staples to outline the shape of the void being filled. This is particularly helpful when forming circular shapes, such as recreating the curve of a baluster or molding. It also helps to anchor the patch, and can help prevent sagging on vertical surfaces. When filling larger holes on flat vertical surfaces, the epoxy can be covered with a piece of plastic or wax paper, with a flat board tacked on top to keep the patch from sagging out. Once the patch cures, the plastic releases easily from the epoxy.

Epoxies should generally not be used in seams and joints. These areas are designed for expansion and contraction, and are thus heavily stressed. Most epoxy fillers are not designed to move that much. (We have some experience with an exceptional filler - “GFlex” - designed for this kind of use, and will report on the results soon.)NOTE: the epoxy fillers can (and should) be applied on top of the consolidant prior to the application of the paint primer coat. Other fillers, such as spackle, that are used for more cosmetic purposes and/or filling small nail holes, etc. should NOT be applied until AFTER the first coat of primer. This is also true for caulking.

With the proper use of epoxy consolidants and patching materials, virtually any piece of woodwork can be saved. Intricate trim pieces can be shaped, filled, and chiseled to match. However, sometimes it is less expensive to replace rather than repair. An expanse of siding in overall poor condition is an example of the type of condition where replacement often makes sense. Likewise, it can be cost effective to replace all of a given element if some of them are in very bad condition. An example of this occurred recently on one of our jobs where, out of a total of 12 plaster brackets, 5 needed to be replaced and the remaining 7 needed some degree of restoration. In this case, all 12 were replaced. Once we were set up to replace some of the brackets, the replacement of the remaining ones cost only as much as “restoring” them would have. In this way, all of the brackets matched both in appearance and in how long they would last.

Carpentry RelatedLoose and missing trim is often observed on older buildings. General surface preparation procedures often result in the discovery of additional missing pieces, as well as having moldings fall apart in one’s hands. Sometimes it seems that it was only the old paint that held the building together….

PHOTO: loose moldings should be removed and repaired before re-installation.In many cases, it is better to remove many of the deteriorated moldings from the building, dislodge the rusted nails, dig out the rotted wood areas, strip as needed, consolidate and restore, and then reattach them to the building. This work can be done far more expediently, and far more thoroughly, off the building rather than in situ. Some trim elements are composed of many smaller pieces. Attention must be paid to how they come apart – marking each little piece with a pencil is advised. Reattachment of these pieces, as well as resecuring loose trim not removed, should be done with either hot dipped galvanized nails. Screws can also be used- they should be stainless steel, galvanized or “coated” deck screws. Care must be taken with renailing and screwing, as older wood trim is often very fragile and will split easily. Predrilling holes is suggested. Very small pieces are sometimes better off glued.

When pieces are missing or badly damaged, replacement is necessary. Some jobs will call for exact duplication, in which case the pieces will probably have to be milled. This can get rather expensive, especially if only a few feet are needed of several different profiles. However, alternatives abound. Stock moldings from lumberyards will often match “close enough”. Sometimes two moldings can be combined to match a profile. If the majority of a certain molding is in bad shape, all of it can be removed and replaced with a stock molding. In some cases, when there are badly damaged or missing intricate ornaments on a building, one can scavenge parts from less visible areas to use on the more visible areas.

PHOTO: re-installation of loose panels.

The “solutions” are often influenced by how much the owner wishes to spend. The larger the Budget, the more likely one is able to exactly duplicate missing and damaged parts. A larger Budget also enables one to treat surfaces and elements that are in “questionable” condition – i.e. in passable condition now, but long term likely to fail.

It is not always necessary (nor possible) to do the absolute best at every turn. It is perfectly acceptable to perform temporary or shorter-term repairs, as long as one realizes (along with the owner) that the work being done is of that nature. On one project, we were faced with a large plaster gable ornament that was covered with heavily crazed paint. The interior was decayed and honeycombed due to prolonged water leakage. Stripping was not possible due to the fragile condition of the plaster. We presented the owner with three options:

1. Identical Replacement: Remove the ornament and have it resculpted and recast. (Very Expensive.)

2. Like Kind Replacement: Find an existing plaster mold similar in size and shape and use it to replace the existing. (Moderately Expensive- Not always possible.)

3. Restore: Carefully strip as much paint as possible, apply the epoxy consolidant to the surface and interior of the plaster as best possible, prime and then coat it with a flexible patching material. (Not so Expensive.)

PHOTO: application of consolidant to decayed and honeycombed plaster ornament. The consolidant is applied repeatedly over several hours to obtain maximum saturation.

PHOTO: application of Terpolymer Elastomeric coating after the primer coat.

PHOTO: After the Terpolymer coat, two acrylic finish coats and gold leaf were applied. This ornament will now retain its integrity for a long time.

Budgeting Restoration WorkAlthough many of these problems are evident prior to the start of work, careful inspection of the building after scaffolding has been erected and while general preparation activities are taking place usually reveals many more issues that need to be addressed. During the bidding phase, we inform the owner of the type of work needed, and point out some of the obvious conditions. An Allowance is included in the Proposal for “Repairs/Restoration”. Once work has begun, a revised list and Budget for Repairs is presented to the owner itemizing the conditions found and the recommendations for treatment. If conditions that exceed the expertise of the painting contractor are encountered, they should also be pointed out to the owner. Many times, these conditions effect paint job longevity, e.g. roofing, sheetmetal, gutters, structural rot, etc.

Many repairs are relatively easy to perform; general handyman skills are usually enough. Being careful is very important. Not taking on complex jobs initially is good advice- get some experience on smaller jobs. Involve other tradespeople. Hire an experienced carpenter for a week and work alongside in order to pick up tips and techniques. Do not hesitate to recommend to the owners that they talk to specialists when structural issues arise. Find out who is experienced with plaster ornament reconstruction in your area. Experiment with different products and techniques (just be careful where you do so….)

Word to the wise: NEVER agree to perform an unspecified amount of “Restoration” for a fixed price, especially prior to completion of the general surface preparation phase. To do so is to court disaster, as unexpected difficulties and hidden problems ALWAYS arise. One should itemize the work to be performed and specify the number of

man/hours allocated for each procedure and the resulting Budget. At the author’s company, all repair/restoration work is performed on a Time plus Materials basis. Many variables are involved in taking an older, deteriorated façade apart and setting it back right. This work cannot be estimated with any degree of precision.

Primer, Caulk and Cosmetic Filling, and Finish PaintAt this stage, the building has been prepared, deteriorated paint stripped, rusted nails removed, dry-rot areas consolidated and epoxy patched, weathered wood consolidated, loose and missing moldings resecured and/or replaced, sheetmetal and roofing inspected and repaired (probably by others) as needed, gutters cleaned out and the owner informed of any other conditions that might need attention. At this point one is finally ready to do some painting – after all, this is called “Painting Restoration”. However, this article assumes that most painting contractors know what to do from this point on, and so will only address a few salient points regarding these stages of the project.

Primer: If a façade has had extensive stripping and/or Restoration work performed, our experience is that it should receive two coats of acrylic primer. Not oil. The acrylic primers are tenacious bonders suitable for both new and old wood (and plaster, etc.) and also function as tannic acid sealers (found in redwood and cedar). They are also flexible, which is one of the primary reasons to choose them over oil primers. The first coat of primer is applied prior to caulking and cosmetic filler (e.g. spackle, etc) application. The second coat of primer is applied after caulking and cosmetic filling.Caulk and Cosmetic Filling: Use the best caulks possible- the ones that cost $5.00 to $10.00 a tube. Larger seams often need to be filled initially with something other than caulk- “rope caulk” or foam based “backer rod”- otherwise a whole tube of caulk can be shot into a joint and still not fill it up. Regarding “spackle” type products- although vastly improved in the recent years, these products should be used with caution, primarily in smaller voids and nail holes. Extensive use of them in order to “skim out” surfaces that are subject to heavy weathering should be avoided, in our experience. Likewise, because the surface of a sanded spackle-type patch is somewhat soft and powdery, it is also advised that these patches (as well as Epoxy patches, for that matter) be first sealed with the epoxy consolidant prior to priming. Finish Paint: We use 100% acrylic paint. Two coats on the more exposed areas. This means, in some cases, that some areas of a façade may receive a total of 5 coats – First coat- epoxy consolidant, Second and Third coats- primer, Fourth and Fifth coats – finish paint.

ConclusionA “Painting Restoration” is as much an attitude as it is specific products and techniques. It takes hard work and a dedication to attacking the causes of exterior paint failure, not just the symptoms. It must be desired. It is an approach that pays off in the long term. The longevity of the resulting paint jobs, and the satisfaction

from delivering solutions, are mighty rewards.