DREAMHILL
DOME PROJECT
Painting & Sealing
Surface Preparation included scraping and grinding off cement debris
And brushing off the dome
The Dome Painting Job
Rich Cassidy on the rope harness and Eric comes to assist again on the right giving some experienced rope climbing advice
Below Rich operates the sprayer while Joe does the back rolling and John mans the paint pump
Triangle by triangle they work thier way around the dome on each level
After completing the upper 3 levels the lower level is then painted
There are 4 triangular levels of the dome shown here highlighted with different colors
Painting Plan
The path of painting the upper 3 levels is illustrated below.
Note dark areas indicate areas that are painted last moving down the ladder
1. Starting from the top accessed by ladder on right side of balcony using rope and harness have 50 foot paint hose feed through pipe at top of dome to paint pump below in dome. Start at one side of ladder paint the seams and triangles of level 2 all the way around to the other side of ladder. When painting level 3 paint the tops of the dormers that are connected to those triangles.
2. Once level 2 is painted coil up excess rope so it doesn't drag on the painted triangles on level 2 and paint starting at the ladder level 3 all the way around to the other side of the ladder.
3. Once level 3 is painted coil up excess rope and drop it down pipe hole at the center to get it out of the way of painting level 4 and paint starting at the ladder level 4 all the way around to the other side of the ladder then paint the unpainted path back down the ladder, collapsing the ladder to allow the area underneath the ladder to be painted all the way down to level 1.
4. Once the upper levels of 2, 3 and 4 are painted, use a ladder to move around the dome and paint level 1 all the way to the ground, masking off areas such as the porch and exposed concrete floor to keep unpainted.
The above procedure is for first sealing the dome with concrete primer and allowing to dry overnight and then the same sequence is used to apply the Lexan paint afterwards the next day. Painting is done in the afternoon allowing the dome to cool after painting to avoid air bubbles from increasing heat.
Paint Specifications
Sherwin Williams
Mindful Grey SW 7016
100% Arcylic Super Paint Satin Finish
Cement Primer
Loxon 824W300 (aidome
recommendation)
Loxon Block surfacer White (Rob from SW recommendation)
| Sherwin-Williams Order 8157-0033101 Exterior Specialty CONFLEX XL ELASTOMER/ACRYL SMOOTH STANDALONE MC-15071 SW 7016
FIVE GALLON EXTRA WHITE |
Above Elastomeric used for seams did not match the latex color and does not come in satin finish
Below is a color match from a cement paint sample which I'll use to paint over the existing elastomeric paint
Sherwin-Williams Order 8157-0044211 Exterior Architectural MC-18659
FIVE GALLON EXTRA WHITE |
SEALING THE DOME
(Excerpts from the Dome Construction Manual)
OVERVIEW
The most common method of water proofing a roof is shingles. The water penetration is partially stopped with the shingle but it is the roofing felt (tarpaper) under the shingle that completes the process. These systems provide ten to twenty years without maintenance but when they begin to leak the entire system must be replaced. On the American Ingenuity dome the water penetration is stopped on the outside surface. Although occasional maintenance is needed to keep the dome sealed it has the advantage of being much easier and cheaper to repair and maintain.
Sealing our dome is done in a progressive process of elimination. Most leaks are eliminated with the first and second coat of paint. The more stubborn leaks will receive additional coats or maybe a special treatment.
There are elaborate
and expensive products available for stopping water from going through concrete.
Through years of experimenting and analyzing what it takes to prevent leaks
we have come to the conclusion that success can be had with ordinary products
from a paint or hardware store. One of the main requirements for success is
a little persistence and the ability to climb up on or get to the suspect
spots on the dome. Once you have reviewed and utilized this information you
can stop any leak. When leaks have been cured the dome will only need an occasional
painting.
THE FIRST COAT APPLIED DIRECTLY TO THE CONCRETE
There is no specific material that is either recommended or required. The primary objective of the first coat is to assure that it will be compatible with concrete, adhere well and make a permanent bond with the concrete. This first coat may also fill and seal most of the pores in the concrete as well as stopping most leaks. With color added to this material it can give you a sample of the final appearance. Paints that best fit this description are concrete sealers or concrete primers; they can be either oil or water based. If the concrete has aged (see Efflorescence) you can go directly to latex house paint and make the first coat a color test.
Because it is advantageous for the product to soak into the concrete, choose something that is not thick or creamy which would just lay on the surface. Most products can even be thinned a little to help them soak into the pores. An application of diluted paint will better seep into the pores than full strength paint. See the instructions on the can for thinning. Any place that the water would penetrate through the concrete, the paint or sealer can also penetrate and solidify, plugging the path.
If the concrete has not aged or weathered for a few weeks you will need to be concerned about the inherent alkaline content of the fresh concrete. You can get a product from a paint store that will allow you to test the alkalinity of the new concrete. You can also apply a concrete sealer that is alkali resistant to any concrete that has been applied recently. Or you can wash the dome with 5% solution of muratic acid and water to dissolve the alkali and then rinse.
If mold has started to grow on the concrete it will have a different color, maybe resembling dirt that won’t wash off easily. Spray the dome with a 10% mixture of chlorine (or 25% bleach) and water to kill the mold. A pump-up garden sprayer works great.
Sherwin Williams makes
a concrete primer that is recommended by our most experienced dome builder.
It is Loxon Acrylic Primer A24W300. It can be applied over new concrete that
has weathered a few weeks and been washed with rain or water.
Richard’s Paint Mfg. Co. also has an excellent primer that is distributed
in Florida. It is Pliolite SR-948
If the concrete is clean and weathered, you can paint it with almost anything. The best choices are either acrylic latex house paint, concrete sealer, or oil based paints intended for concrete.
Do not use anything that produces a water-repellent surface or anything that would prevent the next coat from adhering.
Do not apply an elastomeric paint over the entire surface of the dome or directly to the concrete. We only recommend applying the elastomeric paint in the area of a reoccurring leak.
Avoid painting hot concrete or when the concrete is going to be increasing in temperature over the next couple of hours. That added heat can cause air that is trapped in the concrete to expand and bubble to the surface leaving a small hole or path for water to penetrate later. It is best to paint the first coat when the dome is in the process of cooling off because it has a tendency to suck the paint into the concrete. Also do not paint at temperatures lower than what is recommended for the product.
During and after the
first paint coat application, inspect all seams between panels and joints
between the actual dome shell and adjacent structures such as dormers, entryways,
and links for visible cracks, voids or holes in the concrete. Massage Acrylic
Latex caulk with your finger into these openings prior to applying the top
coat of paint.
THE TOP COAT OF PAINT
This can be applied as soon as the first coast has dried. Delaying the final coat that is applied over the entire dome until you have sealed and stopped almost all of the leaks allows this coat to act as additional sealant and also give the dome a uniform texture and color. Otherwise, after you have treated some locations for leaks you may need another topcoat over the patch to match the color. All of the treatments needed to stop future leaks can be applied on top of this coat. Also think of it as the coat that gives you the final color and appearance.
For the topcoat we recommend a 100% Acrylic paint. It is a typical house paint and any reputable brand should be OK.
A flat paint will not show imperfections in the surface as much as a semi-gloss but the semi-gloss will last longer and clean up easier. A good intermediate choice is Eggshell or Satin finish.
The final coat should be full strength to obtain maximum life and duration. When you apply the final coat don't wait till the roller gets dry before re-dipping it. In other words, don't put it on thin because that will reduce its life. If you are covering more than 250 sq. ft. with a gallon of paint it is going on too thin. Applying the paint too thin will just cause you to repaint sooner.
Choose any color you like but select a light shade. White will be blinding and anything darker than the bare concrete will produce higher surface temperatures and more expansion in bright sunlight.
Adding fine aggregate to the paint will allow you to make a more uniform texture over the dome blend in the concrete that was applied in the seams
After the final coat is applied, and there are no apparent leaks, a water repellant sealer can be applied. These usually contain silicone. This is not needed but it will cause the dome to shed water and dirt a little faster. The water repellant characteristic will wear off in a couple of years and by the time you need to repaint the dome the new paint will adhere.
When you rub your
finger across the paint and remove a chalk like residue it is time to repaint.
WHEN YOUR DOME HAS LEAKS
First realize that you don't have a problem with the entire dome. I have had dome owners think that they needed to resort to some elaborate process or coating and start over with sealing the dome. It usually turns out that they only have a few leaks that they haven't been able to fix. Apply this information and if you can't eliminate the leaks call us.
Just after the first application of paint or sealer you can expect to still have leaks. At this time mark the location of remaining leaks and apply another coat of paint or sealer to the suspected area. With this method of elimination you can seal and stop almost every leak if the paint or sealer is applied in the correct place.
When a total of two to three coats of sealer or paint does not stop the leak, either the water is coming in at a place different than where the sealer is applied or you will need to suspect one of the causes of reoccurring leaks.
REOCCURRING LEAKS
Because concrete is a rigid material, porous leaks through the concrete can be sealed by filling the water path with paint or sealer. These leaks will remain sealed as long as there is no separation or movement in the concrete. When there is movement or separation in the concrete this sealing method will only last until the movement reopens the path for water to pass through.
For those with an older dome that has been painted previously, all of the remaining leaks are probably the reoccurring type.
With the experience we have gained over the years we can not only predict where the problem areas are but we know why they occur and how to correct them. Because these leaks result from movement within the concrete shell, a stretchable patch is required to stop the water penetration at the surface. Later we will elaborate on how to provide a patch on the outside of the dome that will stretch and allow for the movement while stopping the water before it reaches the concrete.
CAUSES OF REOCCURRING LEAKS
There are three typical conditions that cause and contribute to reoccurring leaks: 1) substandard concrete 2) concrete layers not bonded together or 3) a crack in the concrete with movement between the two parts.
SUBSTANDARD CONCRETE will likely be the result of an incorrect mixture or too much water added to some of the mix. A leak or change in the exterior texture (blisters, distortions, etc.) can indicate this problem and it is easily confirmed with a hammer. Test for loose and substandard concrete. The concrete should withstand a moderate hammer blow without crumbling. Paint or sealer can not stop water penetration if the concrete tends to crumble or deteriorate. An elastomeric patch may fix a small area but most of the time the concrete will have to be chipped away and replaced. Any concrete that can be easily chipped out should be removed and replaced. Be sure to use the concrete bonding techniques described in the assembly manual when replacing substandard concrete.
CONCRETE LAYERS NOT BONDED TOGETHER, particularly in the seams, are a common cause of reoccurring leaks. Sometimes an air pocket or void in the concrete is the culprit. In these conditions there is movement in the concrete and the leak can not be permanently stopped by a sealer or paint. The paint or sealer works for a while and with time and temperature changes a void will open allowing water to penetrate.
Loose layers in the concrete and voids can easily be located by tapping the suspected area with a hammer. This should be suspected in the seams and other areas where the concrete was applied on site. There will be a very distinct and easily noticed difference in the sound when the concrete is not solid.
When you locate loose concrete there are two possible remedies. One is to remove the loose concrete, clean and wash the adjacent concrete, apply bonding agent to the joint and refill the void. The other remedy is to apply a patch that will not be affected by the movement of the loose concrete. See elastic patch description below.
CRACKS IN THE CONCRETE: At locations where a link connects to the two domes, where a entryway connects and sometimes where a dormer connects there is enough expansion and contraction from temperature changes that a crack will occur which will allow water to penetrate. Unless this crack is wider than a credit card it will not have any structural significance and will often not even be visible. If you can't see the crack assume that it is the upper corners where the link, entryway or dormer connect to the dome. The suspected location can also be described as the joint where the spherical shape meets the outward projections of the openings.
SEALING REOCCURRING LEAKS
Leaks that reoccur after they have once been eliminated are caused by movement in the concrete. These will require an application on the outside of the dome that will stretch and allow for the movement.
CHOICES
CAULK: If the crack is visible you may be able to apply a bead of caulk with
a thickness of about 1/4" directly over the crack and tapering on the
edges to blend with surface. Then paint to match the dome. Don't use Silicon
caulk next to concrete. A Urethane or Butyl caulk is the best choice for concrete.
ELASTOMERIC PATCH: Purchase an elastomeric patching material from a hardware store. This is a little thicker than paint and can be put on with a brush or putty knife to a thickness of about 1/8" or more. The thickness is required to allow for the expansion without tearing. A common product available is KoolSeal, a white roof coating often used on mobile homes.
ELASTOMERIC PAINT AND FABRIC: We have a stretchable synthetic fabric that is sandwiched between two coats of elastomeric paint. The fabric allows the elastomeric paint to be applied thicker than normal and it also reduces cracking or tearing of the coating. When this is applied you can be assured that water is not going through it. If you would like to order the Spun Flex fabric from us, it is $3.00 per sq.yd. Available in 12’ and 36” wide strips.
KoolSeal Company also has Reinforcing Fabric which you may find at your local hardware stores that carry KoolSeal.
TYPICAL LOCATION OF
LEAKS
Most reoccurring leaks are on the South side where the sun causes the maximum
temperature variations. This is additional evidence that the reoccurring leak
is movement in the concrete caused by the thermal expansion.
ENTRYWAY, DORMER OR
LINK
If the leak is at an entryway, dormer or link you will need to apply an elastic
patch or maybe caulk if you can see the crack. If you can't see the crack
assume that it is the upper corners where the link, entryway or dormer connect
to the dome
ALONG A SEAM
If the leak is along a seam it is probably a layer of concrete not bonded
well to the layer below. Do the tap test along the seam and you may be able
to identify the exact location or locations. Just because the seam sounds
hollow or loose does not necessarily mean that it will leak. Problem seams
can be sealed with the Elastomeric Patch or Elastomeric Paint and Fabric.
LEAKS AROUND SKYLIGHTS
The location of a leak at a skylight will give you some clue as to the cause
or cure.
The most likely source of a skylight leak is at the joint where the outside aluminum trim pieces are but together. Caulk or apply multiple coats of elastomeric paint along all three sides of these joints if they are a suspect. Caulk applied on the glass side of the aluminum trim will be less noticeable if it is clear. Because it is not in contact with concrete it is OK to use Silicon caulk.
Always clean the surface to assure a longer lasting adhesion. A stiff brush scrubbing with Lacquer thinner or methyl alcohol wiped up with paper towels will usually do the job.
Leaks at the top of a skylight will more likely be where the aluminum seals to the concrete than where the aluminum seals to the glass because the latter would require the water to travel uphill. This is not always true because wind can push the water up through a joint. For additional sealing where the aluminum meets the concrete use Urethane or Butyl caulk or multiple layers of elastomeric paint. If you haven't already, consider painting all of the aluminum to match the dome.
When the leak is not along the top of a skylight, the probability increases that water is leaking past the seal between the glass and aluminum. The best caulk for this is a brand named Lexel, It is Clear and also comes in a clear tube. A 100% Silicon clear caulk is also a good choice. Because these caulks are clear, when a small bead is applied to the joint between the glass and the edge of the aluminum it will not be noticeable. If the glass and aluminum are cleaned well, this method will likely seal this joint without having to remove the aluminum.
CONDENSATION
If the leak appears at the bottom of the skylight, be sure that it is not
just condensation on the glass that has run to the bottom. Anytime condensation
is a problem, consider painting the area with a semi-gloss paint and install
a miniature spout to cause the drip to fall to the floor rather than run down
the wall. A piece of semi-stiff clear plastic from a discarded package (like
bubble wrap) works fine. Paint will hold it in place.
OTHER CAUSES
On occasions the dome concrete can be solid and water will penetrate through the paint and concrete. This condition is basically caused when air escapes from the concrete just after the paint is applied. When this occurs you can see it in the texture of the paint as tiny pinholes sometimes resembling miniature volcanoes with raised edges. These very small pores through the paint and concrete. Most likely the evidence of this kind of leak is in the form of a blister on the interior surface or a damp area showing up after a long drizzling rain. The cure is to repaint the area while the dome is in the process of cooling. Use a thinned paint and continue brushing or rolling if and when the pinholes appear.
The source of a leak can easily be a window. Sometimes rain that is blown against the glass and runs down into the frame will leak into the wall because the drain hole of the window is stopped up or the window frame has a leak in it.
When moisture or a leak shows up along the bottom of riser panels, it could be the result of ground water wicking (soaking) up between the foundation and the panels. If this is likely, lower the ground level or diverting the water away from the dome.
THINGS YOU SHOULD KNOW
LATEX & 100% ACRYLIC PAINTS
Around 1948 Latex
paints became the first water-based alternative
to oil-based paints. Many improvements have been made but perhaps the most
significant is the introduction of Acrylic Resins. Paint of 100% Acrylic are
more resistant to ultraviolet rays, retain their color longer, less prone
to chalking, retain their elasticity, more alkaline resistant and can be cleaned
up with water.
We recommend using a 100% Acrylic paint as the final coat. Once you reach
this level of quality there is little advantage in selecting a more expensive
paint.
ELASTOMERIC PAINTS
These are Acrylic paints that have a considerable capability of stretching. They are useful in sealing limited locations on the outside of the dome where thermal expansion is most likely. Most all paints will stop liquid water if there are no holes or cracks, but water vapor (evaporated water) is a gas which will pass fairly easily through most Latex paints. Elastomeric paints restrict the amount of water vapor which will pass through them. This can be a disadvantage if there is lot of water vapor confined inside the dome. The water vapor will slowly pass through the EPS and quickly through the concrete and practically come to a stop at the paint. In extreme conditions the paint will be lifted in a bubble or blister that may be filled with water which condensed from the original vapor. The blisters can be prevented by venting the moisture, delaying the application of elastomeric paint until the plastering and other wet materials have dried or priming the concrete with a oil-base concrete primer.
We only recommend using elastomeric paint on problem areas where stretching is needed. There is no advantage to painting the entire dome with it and in many cases it will cause the problems mentioned above if it restricts the flow of water vapor.
EFFLORESCENCE
Simply stated, efflorescence is crystallized deposits, usually sodium sulfate, which can appear on the surface of cement type materials. These are chemicals that naturally occur in concrete and are brought to the surface by moisture in the concrete. When that moisture evaporates it leaves a white fluffy deposit called efflorescence. A significant amount of these deposits will break down the adhesion of the paint, resulting in flaking and peeling. To insure a lasting bond between paint and concrete, either delay the painting for approx. 30 days, allowing the concrete to fully cure and most of the deposits to come to the surface and be washed off with rain etc. or prime the surface with a alkali-resistant oil base primer.
SMALL CRACKS IN THE CONCRETE
Small cracks are often occur when the concrete dries and shrinks due to the loss of moisture. These shrinkage cracks are only a few inches long, do not go all the way through the concrete and they are often in random directions. When they are filled with paint or a sealer they will not leak again.